1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 242.289 244.499 246.819 249.623 252.981 256.514 259.919 263.126 266.278 269.394 272.647 275.854 279.04 282.193 285.108 287.985 290.85 293.657 296.41 299.103 Year Millions