*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
19873
19880
198913
199011
199123
199237
199347
199422
199515
19966
199734
199824
199918
20003
20014
20026
200336
200444
200576
200627
200730
200836
200939
201040
201154
201256
201354
201470
201566
201661
201746
20180
Total1001