From the press release:
Total state government revenue increased to $2.0 trillion in 2010, up 79.0 percent from $1.1 trillion in 2009, resulting mainly from large increases in social insurance trust revenue, according to the latest findings from the U.S. Census Bureau. After a substantial loss in earnings in 2009, trust systems showed earnings of $450.5 billion in 2010, a gain of 218.2 percent over the year before.
Two major sources make up these trust systems: (1) employee retirement systems and (2) federal and state social insurance trust systems, which include the unemployment compensation system, state government worker’s compensation programs, Social Security, Medicare, veteran’s life insurance and railroad retirement.
Earnings on these systems vary widely year to year because state retirement systems invest heavily in financial markets and respond to shifts in market performance. More detailed statistics about the state retirement systems will be available with the upcoming state retirement data release in the first quarter of 2012.