*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000101
1982000000
1983000000
1984000000
1985000000
1986000000
1987000112
1988000000
1989000000
1990000011
1991000213
1992000101
1993000011
1994000022
1995000448
1996000336
1997000437
1998000314
1999000415
2000000145
2001000303
200200011112
2003000707
2004000303
2005000101
2006000202
2007000808
20080008210
2009000112
201000013619
201100020222
2012000145
2013000404
2014000101
2015000101
2016000000
2017000000
2018000000
Total00010838146