Henry 18Z pressure
1993       -   690.3   690.8   687.9   684.4   683.9   682.3       -       -       -   692.7   691.1
1994   698.0   689.8   685.3   691.9   685.3   701.2   685.4       -       -       -   695.3   690.2
1995   691.3   692.0   691.4   686.1   681.8   691.2   696.3   686.0       -       -   693.6   693.2
1996   698.2   698.5   688.5   691.3   687.4   687.8   685.1   696.9       -       -   697.4   699.7
1997   697.8   691.7   683.7   689.6   683.3   689.2   679.2   684.1       -       -   702.5   696.9
1998   696.5   693.7   688.6   678.6   685.4   690.3   683.9   682.8       -       -   688.2   693.0
1999   700.5   695.2   691.5   681.9   685.9   698.6   685.4   684.7       -       -   689.8   688.9
2000   691.0   690.4   691.5   689.8   686.4   691.4   687.9   687.1       -       -   697.9   701.3
2001   697.1   697.7   688.4   686.0   691.0   689.7   689.4   680.0       -       -   691.1   693.3
2002   696.0   690.7   694.7   689.6   696.5   687.4   690.8   679.9       -       -   688.3   690.8
2003       -       -       -       -       -   693.8   688.2       -       -       -       -       -
2004       -       -       -       -       -       -       -       -       -       -       -       -
2005       -   691.9   692.9   689.2   691.2   694.1   685.8       -       -       -   691.5   706.9
2006   698.6       -       -       -       -       -       -       -       -       -       -       -
2007       -       -       -       -       -       -       -       -       -       -       -       -
2008       -       -       -       -       -       -       -       -       -       -       -       -
2009       -       -       -       -       -       -       -       -       -       -       -       -