11.9: The percentage of American workers in unions last year, the lowest proportion in more than 70 years, according to the government’s Bureau of Labor Statistics. The number of workers in unions fell by 612,000 last year, to 14.7 million. About 20 percent of workers were in unions in 1983; the figure was 35 percent during the mid-1950s, according to labor historians. 

See article at: NYT 23Jan11 – Prime Number