Year	mm Hg
1980	124.4
1981	124.4
1982	124.3
1983	124.2
1984	124.3
1985	124.4
1986	124.5
1987	124.6
1988	124.8
1989	124.9
1990	125
1991	125.1
1992	125.2
1993	125.4
1994	125.5
1995	125.6
1996	125.7
1997	125.9
1998	126.1
1999	126.3
2000	126.5
2001	126.7
2002	127
2003	127.2
2004	127.4
2005	127.6
2006	127.7
2007	127.8
2008	127.8