Year	mm Hg
1980	131.2
1981	130.7
1982	130.3
1983	129.8
1984	129.3
1985	128.9
1986	128.5
1987	128.3
1988	128
1989	127.8
1990	127.7
1991	127.5
1992	127.3
1993	127
1994	126.8
1995	126.4
1996	126.1
1997	125.7
1998	125.3
1999	125
2000	124.6
2001	124.3
2002	124
2003	123.7
2004	123.3
2005	123
2006	122.7
2007	122.3
2008	122