Year	mm Hg
1980	129
1981	129.1
1982	129.1
1983	129
1984	128.9
1985	128.9
1986	128.7
1987	128.6
1988	128.5
1989	128.4
1990	128.3
1991	128.2
1992	128.1
1993	128
1994	128
1995	127.9
1996	127.9
1997	127.8
1998	127.8
1999	127.7
2000	127.7
2001	127.7
2002	127.6
2003	127.6
2004	127.5
2005	127.4
2006	127.3
2007	127.1
2008	127