*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 19703007010
1970000000
1971000000
1972100001
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985100001
1986000000
1987000000
1988100001
1989000101
1990001102
1991100102
1992000101
1993200002
1994004408
1995001102
1996000000
1997000101
1998001001
1999000000
2000000000
2001000000
2002000000
2003000000
2004000000
2005100405
2006104005
2007001416
2008200103
2009001102
20102088018
2011100203
2012001304
2013001001
2014000000
2015001001
2016000000
2017000000
2018000000
Total1602440181