*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970001304
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000202
1978000000
1979001607
1980000303
1981000606
1982000202
1983000112
1984000202
1985001203
1986000426
19870039113
198800210012
198900011213
199000314522
199100928441
199200526233
199300424634
1994006311249
199500439750
1996006311653
1997003511771
199800324734
199900128736
2000004974105
20010041091114
20020001050105
20030051071113
200400139545
200500358667
200600554463
200700162063
200800162164
2009003981102
20100031230126
20110011321134
201200582289
201300065065
201400186125
201500107219
2016000202
2017000224
2018000000
Total0011615671201803