Lettau 18Z wind_speed 1986 - 7.8 6.0 9.4 11.0 11.3 8.4 8.5 7.2 9.7 4.7 6.4 1987 9.6 6.4 5.5 5.1 7.4 8.8 5.7 7.0 5.0 0.1 - 8.7 1988 8.0 6.0 9.3 10.4 8.4 10.8 8.9 13.7 9.4 11.9 5.5 6.3 1989 8.4 4.8 8.0 8.2 9.3 5.8 9.9 11.3 11.1 10.7 12.2 6.0 1990 6.8 5.6 6.4 8.6 6.0 10.5 6.5 9.4 8.1 8.6 6.5 11.2 1991 5.4 6.0 8.0 9.0 10.8 7.7 6.8 - - - 8.3 7.1 1992 6.3 8.5 8.1 6.3 8.5 9.7 - - - - 7.3 7.0 1993 6.9 6.8 9.0 7.0 6.0 - - - - - 6.7 4.5 1994 7.8 7.6 8.0 8.6 7.9 9.1 8.4 - - - 6.2 6.8 1995 5.5 8.0 8.0 7.0 8.4 11.0 - - - - 12.7 8.9 1996 8.5 - - - - - - - - - - 6.7 1997 6.7 - - - - - - - - - - - 1998 - - 8.3 6.5 9.1 - - - - - - - 1999 - 6.2 6.4 6.9 8.1 7.5 9.6 - - 9.6 - - 2000 - - 8.6 10.0 8.3 10.7 12.7 7.7 11.8 - - - 2001 - - - - - 10.3 6.4 - - - - - 2002 - - - - - - - - - - - - 2003 - - - - - - 9.2 - - 15.5 - - 2004 - - - - - - - - - - - - 2005 - - - 20.2 - 19.4 34.9 20.2 5.1 18.5 - - 2006 - - - - - - - - - - - - 2007 - - - - - - - - - - - - 2008 - - - - - - - - - - - - 2009 - - - - - - - - - - - -