Year	mm Hg
1980	128.8
1981	128.5
1982	128.1
1983	127.8
1984	127.5
1985	127.2
1986	126.9
1987	126.6
1988	126.3
1989	126
1990	125.7
1991	125.4
1992	125
1993	124.6
1994	124.2
1995	123.7
1996	123.3
1997	122.9
1998	122.4
1999	121.9
2000	121.5
2001	121
2002	120.5
2003	120
2004	119.5
2005	119
2006	118.4
2007	117.9
2008	117.4