Year	mm Hg
1980	131.7
1981	131.3
1982	130.9
1983	130.4
1984	130
1985	129.5
1986	129.1
1987	128.7
1988	128.4
1989	128.2
1990	127.9
1991	127.6
1992	127.4
1993	127.1
1994	126.9
1995	126.5
1996	126.2
1997	125.8
1998	125.5
1999	125.2
2000	124.8
2001	124.6
2002	124.4
2003	124.1
2004	123.9
2005	123.7
2006	123.4
2007	123.2
2008	122.9