Year	mm Hg
1980	123.2
1981	123.2
1982	123.2
1983	123.1
1984	123
1985	123
1986	122.9
1987	122.8
1988	122.8
1989	122.7
1990	122.7
1991	122.6
1992	122.5
1993	122.5
1994	122.4
1995	122.3
1996	122.3
1997	122.2
1998	122.2
1999	122.2
2000	122.1
2001	122.1
2002	122.2
2003	122.3
2004	122.4
2005	122.5
2006	122.7
2007	122.8
2008	123