*Excludes Observations that spanned multiple years

Pre 19701
19701
19710
19720
19730
19740
19750
19760
19771
19781
19790
19800
19810
19820
19830
19841
19852
198617
198720
198810
198939
19903
199121
19928
199312
19948
19955
19962
199715
199811
199912
200031
200124
200213
20038
20049
200513
20068
20077
20085
20096
201018
201117
20125
20135
20147
201513
20169
20179
20180
20190
Total397