*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970002002
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977001001
1978000000
1979000000
1980000000
1981000000
1982001001
1983000000
1984001001
1985001001
1986000000
1987001001
1988003003
1989003003
1990005005
1991007007
1992003003
1993006006
1994006006
199500120012
1996004004
1997006006
199800120012
1999004004
200000180018
200100190019
200200180018
200300190019
2004006006
200500110011
2006003003
2007008008
2008007007
200900100010
2010006006
2011007007
2012006006
2013002002
2014000000
2015002002
2016000000
2017000000
Total0022000220