*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000112
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000101
1980000101
1981000011
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988001001
1989000000
1990000000
1991000000
1992000000
1993000000
1994000101
1995000000
1996000011
1997000011
1998000000
1999000000
2000000101
2001000112
2002000404
2003000213
2004000011
2005000224
2006000000
2007000213
2008000112
2009000101
2010000202
2011000101
2012000011
2013000000
2014000011
2015000011
2016000000
2017000000
2018000000
Total001211436