*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
19903
19911
199216
19933
19947
19956
19962
19972
19984
199910
200019
20019
20028
20037
20044
20054
20060
20072
20083
20090
20103
20113
20122
20130
20140
20150
20160
20170
Total118