*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970401005
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977002002
1978000000
1979003003
1980001001
1981101002
1982001001
1983400004
1984200002
1985200002
1986502007
1987400004
1988301004
1989003003
1990018009
1991412007
1992214007
1993007007
1994224008
19952470013
199634140021
199701100011
199811100012
1999017008
200050120017
20014390016
200201110012
200301110012
200411200022
200505160021
200601110012
200700220022
200801200021
200933340040
201030260029
201180370045
2012008008
2013102003
2014002002
2015001001
2016001001
2017000000
Total643233100427