*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970001034
1970000000
1971000033
1972000033
1973000011
1974001012
1975000033
1976000055
1977000022
1978000044
1979001034
1980000000
1981001023
1982000055
1983001056
1984000033
1985003069
198600201113
19870021912
1988004059
19890010910
199000401317
1991006039
19920070714
199300501015
199400501116
19950060410
199600150621
19970050813
19980060915
1999002046
20000040711
20010060612
200200100313
20030080513
200400120315
20050040812
2006003159
20070090514
200800100414
200900101112
2010004026
201100100111
2012003025
2013004015
2014000011
2015001001
2016000000
2017000000
Total001763212391