*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000101
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978100001
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985000101
1986000000
1987000404
1988000505
1989000000
1990000303
1991000707
1992000808
199300011011
1994000606
199500010010
1996000707
1997000707
1998000606
1999000404
200000011011
2001000808
2002000606
2003000606
2004000303
2005000404
2006000202
2007000606
2008000505
2009000606
201000014014
201110013014
2012000707
2013000808
2014000000
2015000000
2016000000
2017000000
2018000000
Total2001790181