Year	mm Hg
1980	125.3
1981	125.1
1982	124.8
1983	124.6
1984	124.3
1985	124.1
1986	123.9
1987	123.8
1988	123.6
1989	123.5
1990	123.4
1991	123.4
1992	123.3
1993	123.2
1994	123
1995	122.8
1996	122.5
1997	122.3
1998	122.1
1999	122
2000	121.9
2001	121.8
2002	121.7
2003	121.6
2004	121.5
2005	121.5
2006	121.4
2007	121.4
2008	121.3