*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974001001
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984001001
1985001001
1986000000
1987000000
1988000000
1989000000
1990001001
1991000000
1992000000
1993000000
1994001001
1995000000
1996000000
1997000000
1998000000
1999000011
2000000000
2001000000
2002000000
2003001001
2004000000
2005000000
2006001001
2007002002
2008001001
2009002002
2010001001
2011000000
2012001001
2013002002
2014013004
2015003003
2016000000
2017000000
Total01220124