*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
198417
19850
19860
198713
19880
19890
19900
19912
19923
19930
19940
19950
19960
19970
19980
199924
200049
200119
200210
20032
20045
20050
20060
20070
20082
20090
20101
20110
20120
20130
20141
20150
20164
20170
20180
20190
Total153