Year	mm Hg
1980	130.3
1981	130.2
1982	130.1
1983	129.9
1984	129.8
1985	129.8
1986	129.8
1987	129.9
1988	129.9
1989	130
1990	130
1991	130
1992	130
1993	130
1994	129.9
1995	129.9
1996	130
1997	130.2
1998	130.4
1999	130.6
2000	130.8
2001	131.1
2002	131.4
2003	131.6
2004	131.8
2005	132
2006	132.1
2007	132.3
2008	132.4