*Excludes Observations that spanned multiple years

Pre 19700
19700
19712
197289
197373
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
198524
198612
198752
198891
198917
199052
199126
199223
19932
19943
19956
19960
19971
19981
19998
20008
20017
20021
20033
20041
20056
20063
20070
20085
20090
20103
20113
20127
201313
20146
20156
20163
20171
20180
Total558