*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19850
19860
19873
19880
198913
199014
199123
199239
199347
199422
199515
19966
199734
199824
199966
200051
200184
200228
200336
200444
200577
200627
200730
200836
200939
201040
201154
201256
201354
201470
201566
201661
201746
20180
20190
Total1206