*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
1972142
197373
19740
19750
19761
19770
19780
19790
19801
19810
19820
19830
198432
19854
198618
198762
1988151
198934
199088
1991284
199275
199354
199430
19958
19961
19972
199810
199922
200040
200122
200213
200343
200459
200553
200648
200772
200853
200949
201078
201192
201269
201363
201472
201565
201688
201749
20180
Total2120