Year	mm Hg
1980	137
1981	136.4
1982	135.8
1983	135.2
1984	134.7
1985	134.1
1986	133.6
1987	133.2
1988	132.8
1989	132.4
1990	132.1
1991	131.7
1992	131.4
1993	131.1
1994	130.8
1995	130.4
1996	130
1997	129.7
1998	129.3
1999	128.9
2000	128.6
2001	128.2
2002	127.9
2003	127.6
2004	127.3
2005	126.9
2006	126.6
2007	126.3
2008	126