Year	mm Hg
1980	137.3
1981	136.8
1982	136.2
1983	135.6
1984	135
1985	134.4
1986	133.8
1987	133.4
1988	132.9
1989	132.5
1990	132
1991	131.6
1992	131.1
1993	130.6
1994	130.2
1995	129.7
1996	129.2
1997	128.8
1998	128.3
1999	127.9
2000	127.5
2001	127.1
2002	126.8
2003	126.5
2004	126.2
2005	125.9
2006	125.6
2007	125.3
2008	125