*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
19884
19890
19900
19910
19920
19930
19940
19952
19960
19970
19980
19991
200010
20011
20020
20030
20043
20050
20060
20070
20080
20090
20100
20113
20120
20132
20141
20151
20168
20179
20180
20195
20200
Total50