Year	mm Hg
1980	130.4
1981	130.3
1982	130.2
1983	130
1984	129.9
1985	129.6
1986	129.4
1987	129.2
1988	129
1989	128.8
1990	128.5
1991	128
1992	127.6
1993	127.3
1994	127.1
1995	126.8
1996	126.6
1997	126.4
1998	126.4
1999	126.3
2000	126.3
2001	126.3
2002	126.3
2003	126.2
2004	126.1
2005	126.1
2006	126
2007	126
2008	126