*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970233202048
197013220118
1971310037
1972500027
1973400026
1974501028
197518020424
197620020527
19779530623
197835220645
1979434130767
198016170731
1981711501235
198245601227
19837460522
198452501123
1985115801135
1986148901243
19871491701656
198837231701693
19891151801347
1990582401047
1991355440892
1992844401167
199323875012118
1994262114017159
1995141375016118
19968579012104
19978292017119
1998678809110
19992213901476
20007092020119
200110273015100
20029396016124
2003104139116170
20046288016112
200596121018154
2006172172021212
200754148021178
200888174018208
200961224107311
201036430709356
2011692312017400
201234191029227
201351512903152
2014513480066
201553380248
201684250340
20174250112
Total736215320815314691