Year Number of 1986 0.5672 1989 1.957 1990 2.3 1991 1.666 1992 1.392 1993 1.116 1994 1.321 1995 1.464 1996 1.63 1997 1.138 1998 1.459 1999 1.517 2001 1.08 2002 1.785 2003 1.696 2004 1.663 2005 1.783 2006 1.576 2007 1.134 2008 1.07 2009 0.9263 2010 1.022 2011 1.282