*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970001001
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978001001
1979000000
1980000000
1981001001
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988000000
1989100001
1990000000
1991002002
1992000022
1993000000
1994004004
1995100001
1996000011
1997002013
1998003003
1999002013
2000002013
2001001001
2002001012
2003000022
2004002013
2005200002
2006403018
20075040211
2008101002
2009000000
2010001001
2011012003
2012001012
2013102003
2014101002
2015002013
2016102003
2017000000
Total1714101574