*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000011
1970000000
1971000000
1972000000
1973000000
1974000000
1975000101
1976001001
1977000000
1978000101
1979000000
1980000101
1981000101
1982000000
1983000000
1984000000
1985000000
1986000101
1987000112
1988001348
1989001135
1990001056
1991000033
1992000055
1993000123
199400231318
199500022022
199600251219
199700023234
199800512834
199900021113
200000141924
200100021921
200200163037
200300073946
200400043135
200500032124
2006001105061
200700084250
20080014813
2009000122032
2010000111526
2011000222951
201200055661
201300093948
2014000123648
201500012113
2016000268
2017000606
2018000000
Total0017165601783