*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197023000023
1970100001
1971500005
1972200002
1973200002
1974100102
1975100012
1976300205
1977500409
1978500308
1979400307
1980200608
1981300306
1982300104
1983400105
1984400105
1985300104
19867006013
1987500409
1988300306
19894004210
1990300339
19914005110
1992300216
1993400329
199440111723
19952009314
19964019418
19976005718
19985004413
199940031219
20006007417
200140011419
2002200141632
200330063746
200440052231
200550010318
2006111125974
200761013424
200851017528
200911015724
201010018221
201120015017
201220010113
201330091022
201400010818
2015000909
2016000101
2017000202
2018000000
Total17443281229691