Year	mm Hg
1980	128.2
1981	128.1
1982	128
1983	127.8
1984	127.5
1985	127.2
1986	126.9
1987	126.6
1988	126.2
1989	125.8
1990	125.5
1991	125.2
1992	124.9
1993	124.6
1994	124.4
1995	124.1
1996	123.9
1997	123.7
1998	123.4
1999	123.2
2000	123
2001	122.9
2002	122.7
2003	122.6
2004	122.5
2005	122.4
2006	122.3
2007	122.2
2008	122.1