*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 19700016411
1970000000
1971000000
1972000000
1973000101
1974000101
1975000000
1976000000
1977000123
1978000000
1979000000
1980000101
1981000000
1982000101
1983000011
1984000000
1985000000
1986000000
1987000123
1988000101
1989000000
1990000112
1991000101
1992000224
1993000011
199400031013
199500111517
199600011617
1997000066
1998000055
1999000077
2000000033
2001200103
2002000527
2003000538
200400001111
2005000178
2006000101
2007000000
2008000000
2009000000
2010000011
2011000000
2012000000
2013000000
2014000000
2015000000
2016000000
2017000000
2018000000
Total2023599138