Year	mm Hg
1980	131.6
1981	131.2
1982	130.8
1983	130.4
1984	129.9
1985	129.5
1986	129.1
1987	128.8
1988	128.4
1989	128.1
1990	127.9
1991	127.7
1992	127.5
1993	127.3
1994	127.1
1995	126.9
1996	126.7
1997	126.7
1998	126.7
1999	126.7
2000	126.9
2001	127
2002	127.1
2003	127.3
2004	127.6
2005	127.9
2006	128.2
2007	128.6
2008	129