Year	mm Hg
1980	128
1981	128.3
1982	128.6
1983	128.7
1984	128.8
1985	128.8
1986	129
1987	129.1
1988	129.2
1989	129.4
1990	129.5
1991	129.6
1992	129.7
1993	129.8
1994	130
1995	130.2
1996	130.3
1997	130.5
1998	130.8
1999	131.2
2000	131.5
2001	131.9
2002	132.2
2003	132.6
2004	132.9
2005	133.4
2006	133.9
2007	134.5
2008	135.1