*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19842
19855
198617
198732
198812
19895
199014
199134
19928
19933
19941
19958
19967
19975
19981
19997
200024
200142
200216
20031
20046
20053
20066
20072
20082
20091
20100
20111
20123
20134
20143
20153
20162
20171
20180
20190
Total283