Year % of expense 1990 0.35132545512615776 1991 0.8922147071521083 1992 7.581283463955925 1993 5.928853754940711 1994 1.4339377991342983 1995 2.3932163005010687 1996 2.7472061111897017 1997 3.346667967606596 1998 2.4650218715062575 1999 2.5065829451083657 2000 2.0181388899299177 2001 1.6519673471140413 2002 5.797101916722675 2003 4.322962178642781 2004 4.534970257731143 2005 5.436996855993729 2006 4.8748877070548895 2007 6.546715272383838