*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197040001041
1970100001
1971300003
1972300003
1973500005
1974200002
1975200002
1976400105
1977400307
1978100001
197950110117
1980300306
1981500207
1982200406
1983500207
1984300003
1985201104
1986303107
19874033212
19888016015
198910011113
199070218532
199131412323
19925016416
199380110726
1994503281753
199560118126
1996110226544
199760121432
1998901472077
199930119528
200071152566
20011009010
200210027028
200330157061
200410163267
200540046252
200640046050
200780028036
2008160057174
200900029433
201050032138
20111071057120
201240631142
201330114018
201410012133146
201510014419
201640013017
2017000202
2018000000
Total2422448802351403