*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197000001010
1970000000
1971000000
1972000000
1973000011
1974001001
1975000000
1976000011
1977000011
1978000011
1979000011
1980000011
1981001012
1982001034
1983000011
1984001045
1985001001
1986001012
1987005005
1988003014
1989003025
1990003003
199100110011
19920080210
1993004048
1994007007
199500120113
199600110011
1997007029
1998008008
19990060511
2000005005
2001006039
2002009009
200300110213
2004004015
2005004015
200600100010
2007006017
200800100111
200900270027
201000140115
201100370037
2012005038
201300230023
2014004004
2015001001
2016002002
2017000000
Total00272056328