By the numbers: Long-term unemployment

(CNN) -- President Obama and presumptive GOP presidential nominee Mitt Romney both spoke about the economy in Ohio on Thursday. The twin moves by the dueling campaigns are a sign of just how important the economy and jobs will be in November's election.

By the numbers, here's a look at long-term unemployment.

27: Minimum number of weeks that a person must be without a job to be considered "long-term unemployed."

CNNMoney.com: Only 1 in 10 long-term unemployed find work

5.4 million: Number of Americans who have been jobless for more than 27 weeks, as of May.

12.7 million: Number of Americans unemployed as of May.

39: Average duration of unemployment, in weeks, as of May.

42.8: Percentage of jobless Americans considered long-term unemployed.

CNNMoney.com: Long-term unemployment crisis rolls on

21: Percentage of unemployed people under 25 who had been jobless for more than a year, at the end of 2011.

42: Percentage of unemployed people over 55 who had been jobless over a year, at the end of 2011.

63.6: Percentage of Americans counted as part of the labor force in April, the lowest rate since 1981.

Unemployment takes tough mental toll

71: Percentage of long-term unemployed who blame Wall Street institutions for the country's employment situation.

40: Percentage of long-term unemployed who blame President Barack Obama.

69: Percentage of long-term unemployed who say their job loss has not changed their political views.

Photos: A day in the life of America's long-term unemployed

1.2 million: Highest number of long-term unemployed during the presidency of Jimmy Carter (from January 1981, 14.7% of the total unemployed).

2.8 million: Highest number of long-term unemployed during the presidency of Ronald Reagan (from June 1983, 24.6% of the total unemployed).

2.1 million: Highest number of long-term unemployed during the presidency of George H. W. Bush (from October 1992, 22% of the total unemployed).

1.9 million: Highest number of long-term unemployed during the presidency of Bill Clinton (from January 1993, 20.1% of the total unemployed).

2.6 million: Highest number of long-term unemployed during the presidency of George W. Bush (from December 2008, 22.8% of the total unemployed).

6.7 million: Highest number of long-term unemployed during the presidency of Barack Obama (from April 2010, 48.1% of the total unemployed).

Long-term unemployment worldwide

41: Percentage of unemployed workers in France considered "long-term unemployed" as of 2011.

48: Percentage of unemployed workers in Germany considered "long-term unemployed" as of 2011.

49.6: Percentage of unemployed workers in Greece considered "long-term unemployed" as of 2011.

59.4: Percentage of unemployed workers in Ireland considered "long-term unemployed" as of 2011.

41.6: Percentage of unemployed workers in Spain considered "long-term unemployed" as of 2011.