Year	mm Hg
1980	128.6
1981	128.7
1982	128.7
1983	128.7
1984	128.7
1985	128.7
1986	128.7
1987	128.7
1988	128.7
1989	128.8
1990	128.8
1991	128.8
1992	128.8
1993	128.7
1994	128.7
1995	128.7
1996	128.8
1997	128.8
1998	128.9
1999	129.1
2000	129.2
2001	129.4
2002	129.7
2003	130
2004	130.3
2005	130.6
2006	130.9
2007	131.3
2008	131.7