Period	Percent
1970-01-01	0.16
1975-01-01	0.20
1980-01-01	0.51
1985-01-01	1.16
1990-01-01	2.06
1995-01-01	1.92
2000-01-01	1.86
2005-01-01	1.90
2010-01-01	1.94