*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000202
1971000000
1972000000
1973000000
1974000000
1975000000
1976000101
1977000101
1978000000
1979000011
1980000000
1981000000
1982000000
1983000000
1984000000
1985000112
1986000202
1987000303
1988000101
1989000505
1990000224
1991000011
1992000213
1993000134
1994000066
1995000022
1996000235
1997000213
1998000224
1999000224
2000000112
2001000112
2002000729
200300110112
200400010313
200500055156
2006000516
2007000347
200800116118
200900011819
2010000257
2011000101020
20120017917
201300092433
201400061218
2015000336
201600120021
2017000000
2018000000
Total004155161320