*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19851
19863
19874
198822
19893
19905
19915
19923
19939
19947
19954
19963
19975
19981
19991
20001
20010
20020
20033
20040
20051
20061
20073
20083
20094
20101
20113
20121
20132
20142
20153
20167
20172
20180
Total114