The first automatic COLA, for June 1975, was based on the increase in the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W) from the second quarter of 1974 to the first quarter of 1975. The 1976-82 COLAs were based on increases in the CPI-W from the first quarter of the prior year to the corresponding quarter of the current year in which the COLA became effective. After 1982, COLAs have been based on increases in the CPI-W from the third quarter of the prior year to the corresponding quarter of the current year in which the COLA became effective.   Automatic Social Security Cost-Of-Living Adjustments July 1975 -- 8.0% July 1976 -- 6.4% July 1977 -- 5.9% July 1978 -- 6.5% July 1979 -- 9.9% July 1980 -- 14.3% July 1981 -- 11.2% July 1982 -- 7.4% January 1984 -- 3.5% January 1985 -- 3.5% January 1986 -- 3.1% January 1987 -- 1.3% January 1988 -- 4.2% January 1989 -- 4.0% January 1990 -- 4.7% January 1991 -- 5.4% January 1992 -- 3.7%   January 1993 -- 3.0% January 1994 -- 2.6% January 1995 -- 2.8% January 1996 -- 2.6% January 1997 -- 2.9% January 1998 -- 2.1% January 1999 -- 1.3% January 2000 -- 2.5% January 2001 -- 3.5% January 2002 -- 2.6% January 2003 -- 1.4% January 2004 -- 2.1% January 2005 -- 2.7% January 2006 -- 4.1% January 2007 -- 3.3% January 2008 -- 2.3% January 2009 -- 5.8% Before 1975, Social Security benefit increases were set by legislation.