Henry pressure
1993       -   690.4   690.7   688.1   684.4   684.1   682.1       -       -       -   692.9   691.1
1994   698.0   689.9   685.4   692.1   685.0   701.0   685.7       -       -       -   695.4   690.3
1995   691.3   692.0   691.5   686.1   682.1   691.0   696.0   686.9       -       -   693.5   693.2
1996   698.2   698.6   688.7   691.4   687.4   687.9   685.2   696.9       -       -   697.3   699.8
1997   697.9   692.0   683.8   689.5   683.6   689.2   679.3   684.1       -       -   702.2   697.1
1998   696.6   693.9   688.7   678.7   685.5   690.1   684.3   682.8       -       -   687.9   693.0
1999   700.7   695.2   691.5   682.2   685.7   698.6   685.5   684.9       -       -   689.9   688.8
2000   691.0   690.8   691.4   690.0   686.4   691.6   687.6   687.0       -       -   697.5   701.3
2001   697.2   698.0   688.6   685.9   691.0   689.8   689.6   679.8       -       -   691.4   693.0
2002   696.3   690.7   694.8   689.7   696.6   687.7   690.8   679.5       -       -   688.7   690.6
2003       -       -       -       -       -       -   688.2       -       -       -       -       -
2004       -       -       -       -       -       -       -       -       -       -       -       -
2005       -   691.8   693.2   689.1   691.2   694.0   686.3       -       -       -   691.5   707.0
2006   698.6       -       -       -       -       -       -       -       -       -       -       -
2007       -       -       -       -       -       -       -       -       -       -       -       -
2008       -       -       -       -       -       -       -       -       -       -       -       -
2009       -       -       -       -       -       -       -       -       -       -       -       -