*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19902
19915
199211
19936
19945
19953
19968
19972
19982
19997
20006
200110
20022
200314
200420
200523
200621
20077
200827
20096
20100
20117
20127
201310
20140
20150
20160
20170
Total211