Year	mm Hg
1980	136.1
1981	135.6
1982	135.1
1983	134.6
1984	134.1
1985	133.6
1986	133.2
1987	132.7
1988	132.3
1989	131.9
1990	131.4
1991	131
1992	130.6
1993	130.2
1994	129.8
1995	129.5
1996	129.1
1997	128.6
1998	128.2
1999	127.8
2000	127.4
2001	127
2002	126.5
2003	126.1
2004	125.7
2005	125.3
2006	124.8
2007	124.4
2008	124