Year	mm Hg
1980	125.7
1981	125.3
1982	125
1983	124.6
1984	124.3
1985	124
1986	123.8
1987	123.6
1988	123.4
1989	123.3
1990	123.2
1991	123.1
1992	123
1993	122.9
1994	122.8
1995	122.8
1996	122.8
1997	122.8
1998	122.9
1999	122.9
2000	123.1
2001	123.2
2002	123.4
2003	123.5
2004	123.7
2005	123.9
2006	124
2007	124.2
2008	124.3