Year	mm Hg
1980	127.9
1981	127.9
1982	127.7
1983	127.5
1984	127.3
1985	127
1986	126.7
1987	126.5
1988	126.3
1989	126.1
1990	126
1991	125.9
1992	125.9
1993	125.9
1994	125.9
1995	125.9
1996	125.9
1997	126
1998	126.1
1999	126.2
2000	126.3
2001	126.4
2002	126.6
2003	126.7
2004	126.9
2005	127.1
2006	127.2
2007	127.4
2008	127.5