Year	mm Hg
1980	123.7
1981	123.8
1982	123.8
1983	123.9
1984	123.9
1985	124
1986	124.1
1987	124.3
1988	124.4
1989	124.7
1990	124.9
1991	125.1
1992	125.3
1993	125.5
1994	125.7
1995	126
1996	126.2
1997	126.5
1998	126.7
1999	127
2000	127.3
2001	127.6
2002	127.9
2003	128.1
2004	128.5
2005	128.8
2006	129.2
2007	129.6
2008	129.9