Year	mm Hg
1980	131.9
1981	131.6
1982	131.4
1983	131.1
1984	130.9
1985	130.6
1986	130.4
1987	130.1
1988	129.8
1989	129.5
1990	129.2
1991	128.8
1992	128.5
1993	128.1
1994	127.7
1995	127.3
1996	127
1997	126.6
1998	126.3
1999	126.1
2000	125.9
2001	125.6
2002	125.4
2003	125.1
2004	124.9
2005	124.8
2006	124.7
2007	124.5
2008	124.4