Year	Units
1962-01-01	508.0118505485410
1963-01-01	542.1444145449530
1964-01-01	673.3725246670809
1965-01-01	650.3413285724140
1966-01-01	657.5489331056370
1967-01-01	597.8997921410339
1968-01-01	712.6415424687780
1969-01-01	810.2341647691990
1970-01-01	901.5304888566890
1971-01-01	1045.0198112882101
1972-01-01	1139.0500543365800
1973-01-01	1222.6416977161400
1974-01-01	1277.7343070792800
1975-01-01	1340.3659050921099
1976-01-01	1487.3347607465698
1977-01-01	1581.5306958531700
1978-01-01	1686.4966147450500
1979-01-01	1705.1369712964900
1980-01-01	1713.1730361208900
1981-01-01	1906.1214379355600
1982-01-01	2137.0961671151600
1983-01-01	2193.9285430897703
1984-01-01	2369.1478946732900
1985-01-01	2422.0036612502600
1986-01-01	2730.6051197129600
1987-01-01	2705.7513109777100
1988-01-01	2804.0895475401900
1989-01-01	2848.4121731180600
1990-01-01	3201.8333333333300
1991-01-01	3588.7500000000000
1992-01-01	3104.0000000000000
1993-01-01	2472.8333333333300
1994-01-01	2423.5000000000000
1995-01-01	2335.7500000000000
1996-01-01	2498.3333333333300
1997-01-01	2618.1666666666697
1998-01-01	2994.0000000000000
1999-01-01	3373.0000000000000
2000-01-01	3491.3333333333300
2001-01-01	3569.4166666666697
2002-01-01	3616.9166666666700
2003-01-01	3635.0000000000000
2004-01-01	4019.5000000000000
2005-01-01	4043.0833333333300
2006-01-01	4236.4166666666700
2007-01-01	4277.6666666666710
2008-01-01	4363.2500000000000
2009-01-01	3938.7500000000000
2010-01-01	4143.8333333333290
2011-01-01	4156.7500000000000
2012-01-01	4199.8333333333290
2013-01-01	3885.3333333333300
2014-01-01	4149.4166666666700
2015-01-01	3872.7500000000000
2016-01-01	4213.4166666666700
2017-01-01	4397.9166666666700