*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
1972139
197343
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
198410
19854
198611
198751
198890
198925
199073
1991129
199227
199358
19948
19952
19961
199717
199814
199911
200019
200134
200210
20031
200411
20057
20064
20077
20087
20096
20108
201121
201222
201319
201417
201523
201619
201728
20180
20190
Total976