Year	mm Hg
1980	127.8
1981	127.8
1982	127.8
1983	127.7
1984	127.7
1985	127.5
1986	127.4
1987	127.3
1988	127.1
1989	127
1990	126.9
1991	126.9
1992	126.8
1993	126.7
1994	126.7
1995	126.7
1996	126.7
1997	126.8
1998	126.9
1999	127
2000	127.2
2001	127.5
2002	127.7
2003	128
2004	128.2
2005	128.4
2006	128.6
2007	128.8
2008	129