*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000202
1970000101
1971000000
1972000000
1973000101
1974000000
1975000101
1976000101
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985000101
1986000044
1987000538
1988000213
1989000167
1990000066
1991000257
19920003710
199300021921
199400064753
199500052631
199600035154
199700024244
199800125659
199900023234
200000094251
200100036871
2002000112839
200300148489
200400035760
2005000104454
200600073340
2007000113748
2008000162440
2009000202141
2010000312051
201100038341
2012000145
201300001010
2014000358
2015000415
2016000112
2017000022
2018000000
Total0022147891005