*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197274
197329
19740
19751
19760
19770
19780
19790
19800
19810
19820
19830
198447
198521
198623
198710
198868
198961
199036
199195
199239
199322
19942
199516
199614
199711
19986
199979
2000125
200150
200214
20033
20042
20056
20069
20075
20089
20095
20106
201110
201213
20138
201415
201512
201616
201720
20180
Total982