Period	Percent
1970-01-01	1.10
1975-01-01	1.63
1980-01-01	2.50
1985-01-01	3.21
1990-01-01	4.42
1995-01-01	5.75
2000-01-01	7.82
2005-01-01	8.48
2010-01-01	9.08