*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970004004
1970001001
1971000000
1972000000
1973001034
19740040610
1975000088
197600301215
197700501116
197800701219
197900201517
198000101415
198100101819
198200402226
198300501722
198400102021
198502401723
198602901930
1987021202034
198802612332
1989091201940
19900151011945
19910162611760
1992272302153
1993283702370
199422567029123
1995593002266
19963222802275
199711770027115
199813573031140
199901871020109
200002286035143
200127105035149
200231114022140
200313124024152
200437129025164
200500119033152
200605195036236
200702155336196
2008151871027230
2009311185052251
201021211150265
201111312164379
20123115150118647
2013416110121737
2014487010176889
20152897432851272
201641119804241627
201718144314261879
201823145454831947
20191089162693642098
202041195004622417
202133212534822616
202202148423961884
202301180019
202400130316
Total693901655141466621717