*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970200103
1970000101
1971000101
1972000000
1973000202
1974000202
1975000101
1976000303
1977000505
1978000303
1979000101
1980000404
1981000505
1982000303
1983000303
1984000404
1985000606
1986000707
198710010011
198800012012
198900014014
19900027514
199100423128
199200020020
199300019019
199400039039
199500033134
199610030031
199700027027
199800030030
199900030030
200000052153
200110148252
200200052052
200320063166
200400067370
200510154258
20060001042106
20070001093112
20080011287136
20090021654171
20100002476253
20111002160217
2012100771896
20130001620162
20140007443117
201500038038
201600015015
2017000606
2018000000
Total100112023992143