Lettau 06Z pressure 1986 - 991.6 990.1 979.3 992.8 990.7 978.1 979.9 976.2 972.3 974.3 981.8 1987 992.3 988.5 985.7 987.7 982.8 986.5 992.2 975.3 987.7 977.4 978.0 985.4 1988 988.6 983.8 985.1 981.4 988.9 995.4 974.6 975.7 982.1 988.3 981.6 983.4 1989 984.5 985.0 982.8 987.1 968.8 979.5 977.8 982.6 981.6 973.1 975.6 989.2 1990 988.6 982.6 985.7 990.8 996.5 985.1 995.8 979.2 969.9 980.4 982.6 983.5 1991 982.3 989.0 979.9 983.9 986.4 989.2 990.5 - - - 983.1 995.0 1992 988.5 994.4 988.0 984.1 989.4 992.6 - - - - 977.5 982.9 1993 995.7 978.7 985.1 981.0 982.7 - - - - - 979.2 984.0 1994 984.6 982.4 977.6 984.7 984.7 996.8 987.1 973.1 987.6 976.8 984.2 981.2 1995 981.2 980.8 991.0 981.7 981.1 986.1 - - - - 977.0 977.6 1996 985.7 - - - - - - - - - - 985.2 1997 - - - - - - - - - - - - 1998 - - 981.6 974.3 982.1 - - - - - - - 1999 - - 983.9 980.3 976.2 999.3 978.6 981.9 981.0 964.1 - - 2000 - - 983.3 981.9 982.1 984.7 979.3 982.3 987.5 975.6 - - 2001 - - 983.3 977.9 983.6 981.3 985.5 981.8 975.8 971.1 - - 2002 - - 989.7 979.8 991.5 993.9 986.8 977.2 985.8 989.6 - - 2003 - - - - - - - - - - - - 2004 - - - - - - - - - - - - 2005 - - - 977.8 978.0 - 978.3 975.3 - 969.1 - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - - - - - 2008 - - - - - - - - - - - - 2009 - - - - - - - - - - - -