Year	mm Hg
1980	122.3
1981	122.4
1982	122.4
1983	122.5
1984	122.5
1985	122.7
1986	122.8
1987	122.9
1988	123.1
1989	123.3
1990	123.5
1991	123.8
1992	124.1
1993	124.3
1994	124.6
1995	124.9
1996	125.2
1997	125.4
1998	125.7
1999	126
2000	126.2
2001	126.5
2002	126.8
2003	127.1
2004	127.4
2005	127.8
2006	128.2
2007	128.6
2008	129.1