*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197012003015
1970100001
1971200002
1972100001
1973200002
1974100001
1975400138
1976500005
19774007213
1978200248
19795029218
1980200406
198160012018
19824008012
1983401218
1984500207
1985400206
198660012523
1987101111326
198860015324
198990016732
19901001151137
1991504451569
1992100316332
1993506281352
1994904542592
1995110838259
19968013361875
1997140115922106
19981116481581
1999140231451
200080144962
2001101532957
200240258367
20038096023100
2004703671693
20059037936127
2006120612141180
20071400922108
20086021571166
20098163432360
201040153248351
201110054541470
201226153687407
20136042071218
201400063265
201510946258
2016000505
2017001607
2018000000
Total325513830023213791