Period	Percent
1970-01-01	0.50
1975-01-01	0.59
1980-01-01	0.80
1985-01-01	1.27
1990-01-01	2.30
1995-01-01	2.34
2000-01-01	2.70
2005-01-01	4.35
2010-01-01	7.50