Period	Percent
1970-01-01	1.20
1975-01-01	1.33
1980-01-01	1.10
1985-01-01	2.34
1990-01-01	4.64
1995-01-01	8.32
2000-01-01	13.30
2005-01-01	13.93
2010-01-01	14.11