*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977001001
1978001001
197900130013
1980001001
1981003003
1982001001
1983000000
1984000000
1985000000
1986005005
1987003003
1988005005
1989009009
199000120012
199100130013
199200120012
199300200020
199400220022
199500340034
199600250025
199700180018
199800160016
199900140014
200000510051
200100470047
200200510051
200300270027
200400250025
200500230023
200600300131
200700300030
200800350035
200900600060
201000420042
201100710071
201200390039
201300170017
2014001001
2015006006
2016000000
2017000000
Total0078301784