*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19841
19854
19866
198750
198818
198924
199010
19919
19925
19934
19945
199546
19960
199718
19987
19992
200019
20014
20021
20036
20041
20054
20061
200741
200818
200914
20109
201110
201217
201331
201416
20153
20161
20173
20186
20190
20200
20211
20223
20230
20240
Total419