Period	Percent
1970-01-01	0.82
1975-01-01	1.01
1980-01-01	1.20
1985-01-01	1.78
1990-01-01	2.65
1995-01-01	2.83
2000-01-01	3.73
2005-01-01	5.19
2010-01-01	6.84