*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000044
1970000000
1971000011
1972000000
1973000011
1974000000
1975000000
1976000000
1977000000
1978001001
1979002013
1980001001
1981001034
1982001023
1983000022
1984001001
1985002013
1986004015
1987004048
1988006017
1989005016
19900090110
199100250025
199200240024
199300240024
199400340236
199500410142
199600280028
199700360440
199800220123
199900190423
200000170017
200100290231
200200210122
200300150116
200400180018
200500110011
200600150015
200700110617
200800140115
200900360036
201000330033
201100270027
201200120315
201300270027
2014001001
2015002002
2016002002
2017000000
Total00581049630