Year	mm Hg
1980	119.4
1981	119.4
1982	119.4
1983	119.4
1984	119.4
1985	119.4
1986	119.5
1987	119.6
1988	119.7
1989	119.9
1990	120
1991	120.2
1992	120.4
1993	120.5
1994	120.7
1995	120.9
1996	121.1
1997	121.4
1998	121.6
1999	121.9
2000	122.1
2001	122.3
2002	122.5
2003	122.7
2004	122.9
2005	123
2006	123.1
2007	123.2
2008	123.2