Gill 00Z pressure 1985 - 985.2 982.0 984.2 - 980.0 972.2 980.6 971.9 972.9 969.5 978.0 1986 986.7 990.8 989.9 978.6 990.1 988.4 977.8 980.7 977.0 970.7 974.2 980.6 1987 990.2 987.8 986.4 987.3 981.7 984.7 990.0 974.8 986.7 976.6 977.6 983.4 1988 987.1 983.7 985.3 980.8 987.6 993.2 974.1 974.0 981.8 986.4 981.1 981.2 1989 982.8 985.7 982.6 986.3 968.6 979.3 - - - - - - 1990 - - - - - - - - - - - - 1991 - 987.5 979.0 982.7 983.8 987.1 - 979.9 975.0 975.5 980.4 992.7 1992 987.5 993.5 984.5 982.2 987.5 991.0 978.5 983.4 - - 975.8 980.9 1993 994.3 977.0 983.0 978.6 980.8 974.7 968.9 974.7 973.1 973.5 978.0 982.7 1994 983.2 981.7 977.2 982.8 982.1 996.0 985.9 - - - 983.9 979.6 1995 979.2 979.5 989.1 980.7 979.3 983.8 999.5 - - - - 975.8 1996 983.6 988.7 983.4 975.4 983.4 978.7 978.1 984.5 985.1 969.4 985.1 983.0 1997 986.8 988.6 977.9 982.8 969.0 983.6 975.5 973.7 977.6 974.6 984.0 989.6 1998 985.4 979.4 979.1 973.1 979.9 973.2 976.8 975.5 985.8 977.0 970.8 981.2 1999 981.0 985.8 983.7 979.0 974.9 998.1 976.0 981.0 978.0 962.5 969.0 973.6 2000 976.6 982.4 981.5 979.9 980.2 983.1 977.1 980.7 985.7 974.7 978.8 995.6 2001 991.4 986.2 983.1 976.2 981.9 978.8 983.3 981.4 974.8 968.8 973.8 975.1 2002 982.5 975.1 987.4 978.4 989.0 992.9 985.9 975.4 983.7 987.7 983.0 977.7 2003 - - - - - - - - - - - - 2004 - - - - - - - - 977.9 - - - 2005 983.4 974.3 - 974.8 973.9 - 975.5 972.2 - - 975.0 991.1 2006 982.2 - - - - - - - - - - - 2007 - - - 981.7 982.7 981.2 - 974.1 973.9 979.9 979.6 973.3 2008 978.4 978.4 983.4 982.3 980.4 973.7 976.1 980.4 967.2 971.7 - - 2009 - - - - - - - - - - - -