Period	Percent
1970-01-01	0.30
1975-01-01	0.43
1980-01-01	0.89
1985-01-01	1.89
1990-01-01	3.19
1995-01-01	4.61
2000-01-01	5.89
2005-01-01	7.66
2010-01-01	10.13