Year	mm Hg
1980	133.2
1981	133.2
1982	133.2
1983	133.1
1984	133.1
1985	133
1986	132.9
1987	132.8
1988	132.7
1989	132.5
1990	132.3
1991	132.1
1992	131.8
1993	131.5
1994	131.2
1995	130.9
1996	130.6
1997	130.4
1998	130.2
1999	130.1
2000	130
2001	130
2002	130.1
2003	130.2
2004	130.3
2005	130.5
2006	130.6
2007	130.8
2008	131