*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970001001
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982001001
1983000000
1984002002
1985000000
1986031004
1987022004
1988002002
1989062008
1990041005
1991214007
1992061007
199302830031
1994070100080
199501500015
199612830032
199704920051
199813810040
199901500015
200005260058
200111010012
200225940065
200303530038
200406930072
200501620018
200603330036
2007027110038
2008257110070
2009113230037
2010117140032
201117210029
201221820022
2013018180036
2014016100026
2015033006
2016011002
2017000000
Total1471617200902