Year	mm Hg
1980	118.7
1981	118.6
1982	118.6
1983	118.5
1984	118.5
1985	118.6
1986	118.6
1987	118.8
1988	118.9
1989	119.2
1990	119.4
1991	119.6
1992	119.9
1993	120.2
1994	120.5
1995	120.7
1996	121
1997	121.2
1998	121.4
1999	121.6
2000	121.8
2001	122
2002	122.1
2003	122.2
2004	122.3
2005	122.4
2006	122.4
2007	122.5
2008	122.6