*Excludes Observations that spanned multiple years

Pre 197015
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19823
19830
19840
19850
198662
19870
19881
19890
19900
19911
19920
19930
19940
19950
199661
19971
199827
19990
2000273
20014
20020
2003112
200438
200546
20067
20078
20082
20097
20104
20111
20124
20133
20144
201511
201616
20170
20180
20190
Total711