Year	mm Hg
1980	127.2
1981	127
1982	126.8
1983	126.7
1984	126.5
1985	126.3
1986	126.2
1987	126.1
1988	126.1
1989	126.1
1990	126.1
1991	126.3
1992	126.4
1993	126.6
1994	126.7
1995	126.9
1996	127.1
1997	127.3
1998	127.4
1999	127.5
2000	127.6
2001	127.8
2002	128
2003	128.2
2004	128.3
2005	128.5
2006	128.6
2007	128.8
2008	128.9