Year % of total 1990 3.802281368821293 1991 3.9337474120082816 1992 4.785894206549118 1993 4.66321243523316 1994 4.651162790697675 1995 3.89908256880734 1996 3.8461538461538463 1997 3.4261241970021414 1998 3.669724770642202 1999 3.9215686274509802 2000 4.371584699453552 2001 3.8369304556354913 2002 3.87409200968523 2003 4.092071611253197 2004 3.187250996015936 2005 3.3472803347280333 2006 3.7527593818984544 2007 6.97211155378486 2008 11.063829787234042