*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197000104041
1970000011
1971000033
1972000033
1973000055
1974000022
1975000022
1976001045
1977003047
1978000011
197911100517
1980003036
1981002057
1982004026
1983002057
1984000033
1985101024
1986301037
19873230412
19881060815
198911101013
199025180732
199143121323
19921460516
199317100826
1994317280553
199511180626
1996252601144
199714210632
1998120470977
199915190328
200015521766
20010090110
200200270128
200310570361
200412630167
200502460452
200600460450
200700280836
2008015701674
200904290336
201001320538
20117810502122
201261340748
201310150521
201421331404153
201504160727
201600140923
20170530412
201801640222
2019013240037
20200770216
2021010001
Total4627892522731524