*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19862
19877
198821
19896
19905
199112
199212
19932
19947
199512
199616
199711
199820
19990
20009
200112
20020
200319
20044
20054
20066
20076
20082
20093
20100
20111
20122
20134
20143
20151
20167
20174
20180
Total221