*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 19708012011
1970000000
1971000000
1972000000
1973000000
1974000066
1975100023
1976100023
1977100416
1978100427
1979100326
1980000101
1981100416
1982100618
1983001405
1984200204
1985101024
19862016110
19872017515
19882028113
198930110014
199030251020
199110613525
199210213117
199330722638
199450618736
199530318428
199610417325
1997202251039
199830525841
199980020230
200030022328
200120226535
200240030034
200330124432
200440022228
200520244250
200650034241
200740237043
200810055056
20091021230126
20100052060211
20111062211229
20129052712287
20132001182122
2014000707
201500110011
2016000000
2017000000
2018000000
Total9807114871051761