*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970200024
1970043007
197109100120
197206260032
197304120016
197401370020
1975310004
1976001001
1977000011
1978000000
1979013015
1980000011
1981000011
1982000011
1983000000
19840570113
1985001001
1986000011
1987000011
1988008019
1989007018
1990005016
1991202037
19922280012
199310160017
199430130117
199513230027
199621210024
199720140117
199813260030
199900190019
200021180021
200110210022
200210220023
2003005027
200410110113
2005124018
2006102025
20070290011
2008112015
2009016007
201012340037
201120110013
2012206008
2013204006
2014105006
20151190011
2016016007
2017032005
Total3666409026537