*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 19701210050126
1970300003
1971900009
1972600006
1973700108
1974700108
1975700209
197610003013
19779005014
197810001011
197912004319
198012001013
198115002118
198215003119
198313002015
198414000014
198511003014
198615009024
1987210010435
1988190012435
198917007731
1990140293560
19911406161652
19921102154169
199314021595126
1994210532276334
1995192222200245
1996160418340378
1997270426235292
1998220024408454
1999190019220258
2000280433446511
2001270125572625
2002160050464530
2003221152857933
2004230025639687
2005271054440522
2006220295365484
20072230102346473
20081770126284434
200970016597269
20101204255132403
2011160128767371
20123710116118272
201353278193281
20140204167110
2015000332154
2016001221538
2017000000
2018000000
Total8112043182670099709