Year	mm Hg
1980	122.5
1981	122.7
1982	122.9
1983	123.1
1984	123.3
1985	123.5
1986	123.7
1987	124
1988	124.2
1989	124.4
1990	124.7
1991	124.9
1992	125.2
1993	125.4
1994	125.6
1995	125.9
1996	126
1997	126.2
1998	126.3
1999	126.3
2000	126.4
2001	126.4
2002	126.5
2003	126.5
2004	126.5
2005	126.5
2006	126.5
2007	126.5
2008	126.4