Year	mm Hg
1980	122.8
1981	122.6
1982	122.5
1983	122.3
1984	122.2
1985	122.1
1986	122
1987	121.9
1988	121.9
1989	122
1990	122.1
1991	122.3
1992	122.4
1993	122.6
1994	122.8
1995	123
1996	123.2
1997	123.4
1998	123.4
1999	123.6
2000	123.7
2001	123.8
2002	123.9
2003	124
2004	124.2
2005	124.3
2006	124.5
2007	124.6
2008	124.7