Year	mm Hg
1980	130.4
1981	130.3
1982	130.2
1983	130.1
1984	130
1985	129.9
1986	129.7
1987	129.6
1988	129.3
1989	129.1
1990	128.8
1991	128.4
1992	127.9
1993	127.5
1994	127.2
1995	126.9
1996	126.5
1997	126.4
1998	126.4
1999	126.4
2000	126.5
2001	126.6
2002	126.8
2003	127
2004	127.3
2005	127.6
2006	127.9
2007	128.2
2008	128.4