Year	mm Hg
1980	125.4
1981	124.9
1982	124.5
1983	124.1
1984	123.7
1985	123.4
1986	123
1987	122.8
1988	122.5
1989	122.3
1990	122.1
1991	121.8
1992	121.6
1993	121.4
1994	121.2
1995	120.9
1996	120.7
1997	120.5
1998	120.3
1999	120.2
2000	120.1
2001	119.9
2002	119.8
2003	119.6
2004	119.4
2005	119.2
2006	119
2007	118.7
2008	118.5