Year	mm Hg
1980	135.4
1981	134.9
1982	134.3
1983	133.7
1984	133.1
1985	132.5
1986	132
1987	131.6
1988	131.3
1989	130.9
1990	130.6
1991	130.2
1992	129.9
1993	129.5
1994	129.1
1995	128.7
1996	128.2
1997	127.7
1998	127.2
1999	126.7
2000	126.3
2001	125.9
2002	125.5
2003	125.2
2004	124.9
2005	124.6
2006	124.3
2007	124
2008	123.7