*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000101
1970000101
1971000000
1972000000
1973000202
1974000000
1975000101
1976000000
1977000000
1978000000
1979000303
1980000000
1981000000
1982000202
1983000000
1984000303
1985000101
1986000123
1987000718
19880008513
19890008210
199000181928
199100261523
1992001162845
199300155561
199400220164186
199500185362
19960001296108
19970014101106
199800112101114
199900055762
200000021155176
20010008156164
200200022233255
200300018253271
200400110207218
200500114147162
200600231161194
200700040178218
200800139110150
20090005842100
2010000100300400
20110019639136
20120022478104
201300134122157
20140001789106
201500017320
2016000033
2017000000
2018000000
Total001968329753677