*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970007007
1970000000
1971000000
1972000000
1973001001
1974000000
1975003003
1976000000
1977005005
1978001001
1979005005
1980003003
1981001001
1982003003
1983005005
1984000000
1985002002
198600100010
1987009009
198800170017
198900110011
199000120012
199100320032
199200290029
199300230023
199400230023
199500330033
199600230023
199700220022
199800230023
199900190019
200000240024
200100200020
200200310031
200300400040
200400310031
200500300030
200600290029
200700490049
200800350035
200900570057
201000410041
201100330033
20120010200102
20130013600136
20140013000130
20150018900189
20160026100261
20170023600236
20180027700277
20190028500285
2020000000
2021000000
Total002358002358