*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000303
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000101
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988000101
1989000000
1990000101
1991000000
1992000000
1993000000
1994000303
1995000101
1996000101
1997000101
1998000000
1999000000
2000000202
200100214218
200200735446
200300924134
2004000011
2005000718
2006000000
2007000336
2008000101
2009000202
2010000202
2011000101
2012000011
2013000505
2014000202
2015000303
2016000202
2017000000
2018000000
Total001811513146