Year	mm Hg
1980	125.7
1981	125.8
1982	125.9
1983	125.9
1984	126.1
1985	126.4
1986	126.6
1987	126.9
1988	127.2
1989	127.5
1990	127.6
1991	127.8
1992	128
1993	128.2
1994	128.4
1995	128.6
1996	128.8
1997	128.9
1998	129
1999	129
2000	129
2001	129
2002	128.9
2003	128.8
2004	128.7
2005	128.6
2006	128.5
2007	128.4
2008	128.3