Year % of expense 1986 5.5872667398463225 1987 9.437954190046915 1988 7.8605388272583205 1989 7.537385431741438 1990 6.647807637906649 1991 7.371564253849475 1992 8.230516541217249 1993 9.03473044280813 1994 11.637396792708273 1995 12.749220365114406 1996 10.60263120667704 1997 8.649624353595472 1998 8.419715833233834 1999 6.356086692323274 2000 8.343327212082599 2001 8.457437917036643 2002 8.176128193986182 2003 8.969324640475456 2004 9.363404605697214 2005 10.03287210532374 2006 12.798505094945927 2007 9.535541855811893