Lettau 00Z pressure 1986 - 991.8 990.9 979.2 993.0 990.0 978.5 979.7 976.3 972.6 975.2 982.1 1987 992.6 989.0 985.8 987.6 982.9 986.6 992.3 976.0 988.0 977.9 978.1 985.5 1988 988.9 984.2 985.9 981.2 988.8 995.6 974.7 976.1 983.2 988.4 982.0 983.8 1989 985.0 985.5 983.1 987.3 969.3 979.9 977.4 982.5 982.0 973.6 976.1 989.0 1990 989.3 982.9 986.0 991.6 996.2 985.3 995.9 978.9 970.9 980.7 982.9 983.8 1991 982.5 989.5 980.0 984.3 986.8 989.1 - - - - 983.3 995.1 1992 988.9 994.7 988.3 984.1 990.0 992.8 - - - - 977.6 983.1 1993 996.0 979.1 985.1 981.5 982.6 980.6 - - - - 979.8 984.5 1994 985.4 982.8 977.7 984.7 984.1 997.5 987.5 973.1 987.7 977.2 984.6 981.6 1995 981.1 981.1 991.1 982.0 981.5 985.9 - - - - 977.2 977.8 1996 985.9 - - - - - - - - - - 985.4 1997 - - - - - - - - - 978.2 - - 1998 - - 981.8 974.7 982.2 - - - - - - - 1999 - 987.1 984.1 980.7 976.3 999.3 979.0 981.9 980.9 964.4 - - 2000 - - 983.1 982.4 982.2 985.2 978.5 982.5 987.5 975.3 - - 2001 - - 983.6 978.2 983.7 981.3 985.5 981.9 976.5 971.1 - - 2002 - - 989.9 980.2 991.4 993.8 987.1 977.6 985.7 989.7 - - 2003 - - - - - 991.4 - - - - - - 2004 - - - - - - - - - - - - 2005 - - - 978.2 978.2 987.8 978.7 975.2 - 969.4 - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - - - - - 2008 - - - - - - - - - - - - 2009 - - - - - - - - - - - -