Marilyn 18Z pressure 1987 - 987.7 985.2 987.8 983.7 - - - - - - 984.4 1988 987.5 983.5 986.1 984.1 991.0 - 977.1 - - - - - 1989 - 985.4 984.9 - - 981.8 980.8 - - - - - 1990 - 981.2 985.1 - - 987.6 - - 969.7 981.4 982.1 983.3 1991 980.3 986.4 979.7 983.7 986.1 987.4 990.2 980.3 980.4 975.7 981.6 992.9 1992 985.9 993.4 985.8 982.3 988.0 993.0 979.4 982.4 972.2 977.2 975.8 980.4 1993 992.8 976.9 984.5 979.7 - - 970.5 975.7 974.8 974.3 977.5 980.4 1994 983.0 980.9 977.5 983.4 984.0 997.3 987.2 973.2 986.5 976.8 982.5 978.6 1995 978.9 979.8 989.5 981.5 979.3 - - - - - 977.2 976.2 1996 984.8 988.0 982.8 976.7 983.6 980.6 981.0 986.7 986.7 970.6 984.9 983.8 1997 986.5 987.7 977.1 982.9 972.3 986.2 977.5 975.5 979.7 976.3 988.0 988.5 1998 983.2 979.5 980.4 972.9 980.7 976.1 978.0 977.4 986.2 978.7 972.7 979.7 1999 981.3 985.8 982.7 979.5 977.2 997.5 978.7 981.1 981.5 963.7 970.8 972.8 2000 977.0 980.7 982.4 982.5 982.2 983.7 980.9 - - - - - 2001 - 985.8 982.2 977.6 983.0 981.6 985.4 980.1 977.0 971.6 974.9 975.5 2002 980.9 975.9 988.9 979.3 991.5 992.0 986.1 976.8 984.2 987.9 980.8 977.1 2003 - - - - - - - - - - - - 2004 - - - - - - - - - - - - 2005 - - - - - - - - - - - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - 977.5 - - - 2008 - - - - - - - - - - - - 2009 - - - - - - - - - - - -