*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197024011026
1970100001
1971400004
1972300003
1973400004
1974300003
1975600309
19767001210
1977300137
1978600017
1979500016
1980700007
1981900009
19829003012
1983800008
198412000012
198512000012
198611000112
19877005113
198811005117
198910003114
1990110110224
199170124234
1992110128242
1993180154174
1994140024341
1995120141155
1996100224137
1997140116031
1998130120337
1999151112029
2000160125143
2001160020036
2002120124037
2003110213228
200414015222
2005160013130
2006160014131
2007140012127
2008100123034
2009100247059
201050455064
20119001260135
201226031151145
201340069073
2014100214
201520013015
2016000404
2017000101
2018000000
Total469126856361388