*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000415
1970000000
1971000000
1972000000
1973000000
1974000000
1975000101
1976000101
1977000000
1978000000
1979000000
1980000000
1981000101
1982000000
1983000000
1984001001
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991000000
1992000000
1993000000
1994000000
1995000011
1996000000
1997000000
1998001012
1999000000
2000000000
2001000000
2002001214
2003000101
2004000011
2005000123
2006000000
2007000101
2008000022
2009000112
2010000213
2011000202
2012000101
2013000101
2014000000
2015001326
2016000011
2017000101
2018000000
Total004231441