*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197218
19736
19740
19750
19760
19770
19780
19791
19800
19810
19821
19830
19842
19850
198616
198729
198845
198917
199022
199121
199216
199342
19943
199539
19963
19974
19980
199953
200046
200127
20021
20034
20040
200510
20064
20072
200812
20090
201021
201155
20120
20130
20140
20150
20161
20174
20180
Total525