Year	Percent
1987-01-01	0.1298297
1988-01-01	0.1900490
1989-01-01	0.4934860
1990-01-01	0.4953166
1991-01-01	0.3358400
1992-01-01	0.2788934
1993-01-01	0.2846644
1994-01-01	0.1679299
1995-01-01	0.1566837
1996-01-01	0.1505782
1997-01-01	0.1477785
1998-01-01	0.1399582
1999-01-01	0.1336039
2000-01-01	0.1270219
2001-01-01	0.1218722