*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000415
1970000000
1971000000
1972000000
1973100001
1974100001
1975000101
1976000000
1977000000
1978000000
1979000000
1980000000
1981000202
1982000101
1983000000
1984000606
1985000101
1986000000
1987000246
1988000538
1989000112
1990000099
1991001449
19920006713
199310053844
199410111130143
199500010163173
199600411147162
199700156470
199820110204217
199910097383
20000018259268
200110010373384
200210011208220
200300018365383
200410011201213
200500193646
20062013865106
20072112488116
20080013086117
2009000434588
20100046179144
20110016440105
201210154047
2013004273667
2014000115162
2015000819
201600001616
2017000000
2018000000
Total1512347228373348