*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970205007
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978002002
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985001001
1986001001
1987004004
1988001001
1989003003
1990004004
1991004004
1992003003
1993007007
1994014005
1995002002
1996008008
1997005005
1998004004
1999002002
2000016007
2001005005
2002009009
2003013004
2004216009
2005004004
2006103004
2007005005
2008008008
2009014005
2010004004
2011105006
2012110002
2013121004
2014210003
2015320005
2016230005
201718110020
201811500016
2019000000
Total442012400188