*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197000302427
1970001001
1971000044
1972001045
1973000033
1974000044
1975011035
1976001045
1977004037
1978003069
19790060511
19800180918
1981103059
198200401014
19830040711
1984003069
19850020911
19861070715
198700110718
1988241501031
198904260838
199001030619
199109120728
1992244121968
1993217158011242
19942632110011755
1995250874115600
19960116872091249
1997035774013444
19982572508587
199903390850
2000361133017664
2001033020016366
2002048019011510
2003034426013383
2004152522012560
20050461801680
2006132326020370
2007457339111628
200801984429253
2009148371491
2010318410403294
2011215873015248
201202238709319
201302416303190
20140637800141
201505190024
2016051006
2017013004
Total297655134463949428