Year	mm Hg
1980	130.5
1981	130.4
1982	130.2
1983	130.1
1984	129.8
1985	129.6
1986	129.4
1987	129.1
1988	128.9
1989	128.6
1990	128.4
1991	128.2
1992	128
1993	127.7
1994	127.4
1995	127.1
1996	126.7
1997	126.4
1998	126
1999	125.7
2000	125.3
2001	124.9
2002	124.6
2003	124.1
2004	123.8
2005	123.5
2006	123.2
2007	122.9
2008	122.6