What were the data stories of 2011? Which figures gripped the headlines and defined the year? Find our top data stories of the year

What were the headline figures of 2011? Which numbers defined the highs and lows of a news-filled year? From Occupy to the tensions of the eurozone and the riots across England, the Datablog has covered it all. Here is our look back at the year in data.

30

30 workers at Fuskushima power plant had been exposed to radiation over 100msv by May 30 after a Tsunami destroyed the Fukushima plant's safety systems. The recommended maximum limit in one year is 100 msv and a full-body CT scan will expose you to 10msv. Levels reached 400 msv in the first days of the disaster with two workers having received "between 200mSv and 580mSv".

48%

The youth unemployment rate in Spain at 48% is the worst in Europe. Over a million 16-24-year-olds are unemployed in the UK now, the increasing rate of youth unemployment means that we are catching up with the rest of Europe which has had high youth unemployment for a while.

52%

The increase in the interest rate Italy has to pay on the bonds sold to cover its debt is 52%. The way governments borrow money is by selling bonds - the interest rate, or "yield", is set when the debt is auctioned.

This matters because as a country the higher the rate you have to sell your bonds at, the more you'll have to pay back. In short, the lower the figure the better

?10,125,117,000,000

The amount owed by Europe's governments in October 2011 was ?10,125,117,000,000. That's a European average of 80.9% of GDP. But that figure hides a lot of variation: Greece, at the top, owes 151.9%, followed by Italy at 121.4%. The UK is just below average at 80.1%.

3,927

Following the events of the August riots, 3,927 people were arrested during one of the biggest riots England has ever seen with disturbances recorded in London, Birmingham, Manchester amongst others. The arrests were mostly for theft and other 'aquisitive' crimes. In London, the rioters were much more consumerist than in other parts of the country. So, in Croydon, looting was 73% of offences, in Liverpool, 75% of offences were criminal damage.

2.2

The average person accused of a riot-related offence travelled 2.2 miles from home to the riots in England during August 2011. Guardian analysis carried out during the 'Reading the Riots' research, showed that the distance varied between cities - in Manchester, the average from home to offence location was 2.8 miles whereas in Peckham it was 1.5 miles. The animation shown above illustrates the routes taken by the 'riot commuters'.

951

According to the Occupy movement there were 951 Occupy protests in 82 countries on one day in October 2011.

Using Google fusion tables, we mapped all the protest sites including those sent to us by our users.

46.2m

Over 46m people live in poverty in the United States, that's one in seven Americans - up 2.6m on the previous year. That figure is reckoned to be an underestimate - new estimates from the US Census Bureau say it is nearer 49m. 22.7% of the population of Mississippi live in poverty, the highest rate in the country.

99%

Is it really 99% v 1%? It has become the rallying cry of the Occupy Wall Street movement - and the Occupy protests around the world. But is it true?

This is the data behind this animation, produced by Guardian interactive designer Mariana Santos. And that data does show some people have done better out of America's economic booms of the last 20 years than others.

When Americans are asked how US wealth is distributed, they think the very richest fifth should own up to 40% of the national wealth - and that includes 90% of Republicans surveyed. In fact, that richest group owns 85% of the nation's wealth. Those surveyed also thought the bottom 120 million people should own around 10% of the national wealth. The reality: 0.3%

7bn

The United Nations (UN) created a news flurry as they predicted the world population would hit 7bn by the end of 2011. World population has expanded rapidly - in 1950 it was just over 2bn and it is set to reach 10bn in the next 90 years according to the UN's population estimates.

?14,743

The median salary in Dwyfor Meirionnydd, Wales is ?14,743- the lowest in the country. That compares to the median salary for a full-time UK worker ? the rate at which half of UK's employees earn more, and half less ? of ?26,244 in 2011, 1.4% higher than 2010.

Once the country's 5.8 million part-time workers are factored into the picture, though, salaries increased just 0.5% year-on-year, to ?21,326.

672 Libyans

Over 600 Libyans applied for asylum in the UK in 2011 - up from only 65 the year before. Something similar happened with Syria too, but on a smaller scale (129 applications in the third quarter of 2011 compared to 28 in the third quarter of 2010)In 2010, Iranians made the most asylum applications - 10% of the 17,916 total; in 2009, it was Zimbabweans.

The figures also show that net migration to the UK is at a high - not least because the number of people emigrating is at the lowest it's been since the 1990s.

$1.14trillion

The amount of US debt owned by China -
the biggest foreign owner of US Treasury Bonds. As of autumn this year, US Treasury bonds owned overseas accounted for $4.7tn of the national debt - up 8% on last year. That's not everything - the US now owes over $14tn in total.

52%

Of all of the workers in Copeland, Lake District, 52% work in the public sector - the highest percentage in the UK. Twelve local authorities across the UK employ over a quarter of the local workforce. 20% of the workforce are in the public sector now, down from a high of 23.1% in 1992 when the records began.

11,057

The US government has requested information on 11,057 Google users in the first six months of 2011 - almost equal to the number of requests made by 25 other developed countries, including the UK and Russia. Governments around the world requested private data on about 25,440 people.

?395,579,600

Licenses for arms sales granted from the UK to the Arab spring countries in the Middle East and North Africa in the year before revolutions gripped the region.

14,202 strike sorties

Over 14,000 strike sorties were carried out by Nato aircraft over Libya in 2011. The attacks have hit over 3,000 targets - the bulk of them (716) in Tripoli, followed by 492 in Brega.

Nato classifies the biggest number, 304, as ammunition dumps, with nearly 100 tanks and 55 rocket launchers struck. Nato ships have also stopped over 3,000 vessels and boarded another 250 while enforcing the arms embargo.

502

The new number of Westminster constituency seats in England under plans announced by the government and published by the Boundary Commission. Initial analysis by the Guardian data team showed that the Conservatives could have been within striking distance of an overall majority had the 2010 general election been held under England's new boundaries. The Labour party could have netted 14 fewer seats, the Liberal Democrats 10 fewer, while the Conservatives, who dominate England, might have lost just six seats. The UK's only Green MP, Caroline Lucas, would not have been able to win her seat, according to the preliminary figures.

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