Year	mm Hg
1980	128.6
1981	128.9
1982	129
1983	129.3
1984	129.6
1985	129.9
1986	130.2
1987	130.7
1988	131.2
1989	131.5
1990	131.7
1991	131.8
1992	131.9
1993	131.9
1994	131.9
1995	132
1996	132
1997	132.1
1998	132.2
1999	132.2
2000	132.4
2001	132.5
2002	132.6
2003	132.8
2004	132.9
2005	133
2006	133.2
2007	133.3
2008	133.4