*Excludes Observations that spanned multiple years

Pre 197011
19700
19711
19720
19730
19740
19751
19760
19770
19780
19791
19800
19810
19821
19830
19840
19850
19865
198720
1988112
19890
199014
1991153
1992125
1993110
19943
199590
199643
199718
19984
199947
200057
200160
200215
20032
200451
200520
20065
20071
20089
20097
20107
201120
20121
20132
20142
20150
20165
20178
201830
201946
202020
202129
202271
20239
20240
Total1236