Table 2. Data on Incidence Rate of Diagnosed or Suspected Thyroid Cancer Cases by Age Group in Second-Round Screening.

Characteristic	Age Group, y
	≤2	3-5	6-8	9-11	12-14	15-17	18-20	21-22
Examinees, No.	11 270	36 868	49 591	52 798	52 679	29 849	11 569	906
Cases of thyroid cancer, No.	0	0	3	11	25	18	12	1
Mean interval between screening rounds, y	2.3	2.1	2.1	2.1	2.2	2.1	2.2	1.7
Person-years	25 330	76 458	104 579	113 047	113 770	62 080	25 125	1571
Incidence rate, No. of cases per 100 000 person-years	0	0	3	10	22	29	48	64