Year	mm Hg
1980	123.2
1981	123.1
1982	123
1983	122.9
1984	122.9
1985	122.8
1986	122.8
1987	122.8
1988	122.9
1989	123
1990	123
1991	123.1
1992	123.3
1993	123.4
1994	123.6
1995	123.7
1996	123.9
1997	124.2
1998	124.4
1999	124.6
2000	124.8
2001	125
2002	125.2
2003	125.5
2004	125.7
2005	126
2006	126.2
2007	126.4
2008	126.6