*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19732
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19895
19905
199121
19922
19930
19940
19954
19960
199711
19980
19992
20003
20014
20020
20030
20042
20050
20060
20071
20084
20091
20100
20111
20120
20130
20141
20150
20161
20173
20180
Total73