*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970001001
1971000000
1972000000
1973000033
1974002057
1975000077
197600201214
197700301114
197800401216
197900201517
198000101415
198100001717
198200002020
198300201719
198400002020
198502001618
198602501926
198702902031
198802212328
198909801936
1990015311938
19910162111755
1992271702046
1993282602258
19942253902793
1995591602252
19963222102167
19971175102695
199813562030128
19990184902087
200002278032132
20012779034122
20023187022113
200313106024134
200437102024136
20050090031121
200605167034206
200702130333168
2008151501025191
2009311163051228
201021190148242
201111281159343
2012111158095265
20130178038117
20141760033101
2015154802781
2016002003151
2017041203450
20180100910
201928135596
2020001001
2021020002
Total3736623492311633938