Year	Percent
1975-12-31	10.3412
1976-12-31	11.3307
1977-12-31	8.0418
1978-12-31	8.826
1979-12-31	13.6931
1980-12-31	16.6951
1981-12-31	13.3716
1982-12-31	11.8615
1983-12-31	9.8234
1984-12-31	9.5724
1985-12-31	11.9922
1986-12-31	10.6989
1987-12-31	9.4695
1988-12-31	9.7919
1989-12-31	13.4951
1990-12-31	14.4503
1991-12-31	11.3423
1992-12-31	9.2489
1993-12-31	5.6768
1994-12-31	5.1099
1995-12-31	6.3836
1996-12-31	5.8625
1997-12-31	6.5391
1998-12-31	7.1336
1999-12-31	5.2075
2000-12-31	5.884
2001-12-31	4.9458
2002-12-31	3.8827
2003-12-31	3.6159
2004-12-31	4.4342