Priestley_Gl 18Z pressure 1988 - 911.9 - - - - - - - - - 911.4 1989 - 911.5 911.4 914.3 899.1 906.1 906.4 909.9 909.4 903.2 904.7 917.0 1990 916.0 908.2 910.8 918.0 920.9 913.1 920.1 906.4 897.2 907.6 910.7 912.3 1991 909.6 915.4 906.7 912.3 - - - - 907.2 - - 921.4 1992 914.9 919.7 910.9 909.0 913.5 918.2 907.7 908.8 899.7 904.7 - 910.1 1993 - 905.9 910.7 907.0 906.5 901.3 899.0 901.0 901.9 901.2 906.7 909.5 1994 912.5 908.8 903.5 911.3 909.1 923.6 913.1 - - - - 908.4 1995 909.2 - 915.6 908.0 905.5 914.8 924.6 911.0 902.8 906.2 906.7 - 1996 914.3 917.3 912.3 906.6 910.8 908.2 909.4 914.1 915.1 898.9 - 922.3 1997 924.6 923.7 912.8 919.2 909.1 - - - - - - 917.8 1998 912.6 909.8 908.2 901.2 909.4 908.0 906.6 904.3 911.4 906.7 909.1 911.0 1999 911.7 914.4 910.1 904.7 904.3 - - - - - 901.1 903.2 2000 906.8 910.0 910.8 909.8 908.3 909.9 909.6 908.7 912.7 - - 921.7 2001 916.8 915.8 909.6 904.7 911.0 908.7 912.6 905.7 905.1 899.4 904.1 905.4 2002 911.4 905.9 916.4 906.7 917.9 916.7 912.9 902.1 911.5 914.7 909.3 906.3 2003 917.9 916.7 910.9 902.7 904.8 917.2 - - - - 908.3 920.1 2004 911.9 919.7 907.5 905.7 906.1 905.5 900.4 907.0 907.7 906.3 905.9 918.5 2005 914.5 907.0 909.0 905.4 908.3 913.7 - - - - - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - - - - - 2008 - - - - - - - - - - - - 2009 - - - - - - - - - - - -