*Excludes Observations that spanned multiple years

Pre 19702
19700
19712
19720
19730
19740
19753
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19861
198717
198875
198928
19902
199133
199223
199315
19942
199515
199614
19972
19981
19994
200016
20013
20029
20030
20040
20055
20063
20077
20083
20096
20101
20112
20120
20132
20140
20153
20161
20170
20184
20193
20201
20211
20225
20237
20240
Total322