Year	Percent
1980-01-01	2.1876800000000000
1981-01-01	2.5883300000000000
1982-01-01	2.5883300000000000
1983-01-01	2.5883300000000000
1984-01-01	2.4084300000000000
1985-01-01	0.4604830000000000
1986-01-01	1.0496900000000000
1987-01-01	1.1663299999999999
1988-01-01	1.5498700000000000
1989-01-01	2.3368100000000000
1990-01-01	2.2239500000000000
1991-01-01	1.4149800000000000
1992-01-01	2.1018200000000000
1993-01-01	2.0436300000000000
1994-01-01	1.8061200000000002
1995-01-01	2.5845100000000000
1996-01-01	2.9135299999999997
1997-01-01	2.9317300000000000
1998-01-01	2.7487200000000000