*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977001001
1978000000
1979001001
1980000000
1981000000
1982000000
1983000000
1984001001
1985002002
1986003003
1987003003
1988000000
1989003003
1990003003
199100110011
1992008008
1993003003
1994002002
199500110011
199600100010
199700100010
1998006006
199900110011
2000007007
2001004004
200200100010
2003008008
2004008008
2005005005
2006006006
2007009009
200800120012
200900140014
201000200020
201100160016
201200170017
201300100010
2014002002
2015000000
2016000000
2017000000
Total0023700237