Year	mm Hg
1980	131.1
1981	130.6
1982	130
1983	129.5
1984	128.9
1985	128.3
1986	127.8
1987	127.3
1988	126.8
1989	126.3
1990	125.8
1991	125.3
1992	124.8
1993	124.3
1994	123.8
1995	123.3
1996	122.9
1997	122.4
1998	122
1999	121.6
2000	121.3
2001	121
2002	120.7
2003	120.5
2004	120.2
2005	120
2006	119.8
2007	119.6
2008	119.3