Year	mm Hg
1980	126
1981	126
1982	126.1
1983	126.2
1984	126.2
1985	126.2
1986	126.2
1987	126.2
1988	126.2
1989	126
1990	125.9
1991	125.7
1992	125.5
1993	125.3
1994	125.1
1995	124.9
1996	124.6
1997	124.4
1998	124.1
1999	123.9
2000	123.6
2001	123.4
2002	123.2
2003	122.9
2004	122.6
2005	122.3
2006	122.1
2007	121.7
2008	121.4