Year	Units
1973-01-01	1177600900.1741700
1974-01-01	1415484521.8975399
1975-01-01	1384409618.0073600
1976-01-01	1525895147.6348600
1977-01-01	1614392491.4427700
1978-01-01	1656179976.6962400
1979-01-01	1906433120.4019299
1980-01-01	2014179681.1600500
1981-01-01	2268918555.5547500
1982-01-01	2193094748.4187600
1983-01-01	2291919507.5688800
1984-01-01	2516586363.1849103
1985-01-01	2701250457.2332500
1986-01-01	2638978316.8487100
1987-01-01	2740104988.0210900
1988-01-01	3023879082.0936604
1989-01-01	3321671765.8772000
1990-01-01	3440013420.2500400
1991-01-01	3456122565.1572500
1992-01-01	3510211744.4144900
1993-01-01	3470820040.2607500
1994-01-01	4003332049.4466000
1995-01-01	4054835892.6283097
1996-01-01	3748534643.3333300
1997-01-01	4092796778.3333300
1998-01-01	4157211125.0000000
1999-01-01	4360112545.8333300
2000-01-01	4968273996.6666710
2001-01-01	5077831808.3333300
2002-01-01	4955031533.3333300
2003-01-01	5047610966.6666700
2004-01-01	5896179800.0000000
2005-01-01	6379331841.6666700
2006-01-01	7297933941.6666700
2007-01-01	7698064408.3333300
2008-01-01	9611820775.0000000
2009-01-01	7937583066.6666700
2010-01-01	9164620600.0000000
2011-01-01	9943398875.0000000
2012-01-01	10109889116.6667000
2013-01-01	10254365533.3333020
2014-01-01	10205689400.0000000
2015-01-01	10514152966.6666980
2016-01-01	10759675966.6667000
2017-01-01	11849754966.6667000