*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970500106
1970000000
1971300003
1972200002
1973100001
1974100001
1975400004
1976500106
1977500106
1978300003
1979400004
1980600006
1981400105
1982400004
1983400105
1984400004
1985600006
1986700119
1987500117
1988700108
1989600006
1990600017
1991400408
19926001310
19936002816
19949012315
19957030212
19967001816
199710002921
19986011412
19996004111
200010001213
20018017925
20024016213
200390014124
200470061528
20059005115
200610038021
2007100117735
2008100124944
200940215122
2010401291549
2011100125339
2012160010228
2013010326
201400021416
2015000101
2016000101
2017000000
2018000000
Total264116199124604