Year	mm Hg
1980	132.3
1981	131.8
1982	131.4
1983	130.9
1984	130.4
1985	129.9
1986	129.4
1987	129
1988	128.7
1989	128.3
1990	128
1991	127.7
1992	127.4
1993	127.1
1994	126.9
1995	126.7
1996	126.5
1997	126.4
1998	126.3
1999	126.3
2000	126.4
2001	126.6
2002	126.9
2003	127.3
2004	127.7
2005	128.3
2006	129
2007	129.6
2008	130.3