*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197000201113
1970000000
1971000000
1972000000
1973000000
1974000000
1975000055
1976000000
1977000011
1978000033
1979000011
1980001034
1981000000
1982000000
1983000011
1984000077
1985000088
1986002024
1987001056
1988000000
1989002046
1990010001
1991015028
1992011035
1993033017
19940820212
1995050160470
199601570123
199704100216
199801420420
1999002013
2000022015
2001013037
2002004138
2003000011
2004012014
2005001023
2006025029
2007003003
20080180312
200903220530
2010021130034
20110450110
20120840012
2013004004
2014020002
2015000000
2016000000
2017000000
Total0142132193368