http://www.mayomedicallaboratories.com/test-catalog/setup.php?unit_code=...

Reference Values:
INSULIN-LIKE GROWTH FACTOR 1

Males:
0-11 months: 18-156 ng/mL
1 year: 14-203 ng/mL
2 years: 16-222 ng/mL
3 years: 22-229 ng/mL
4 years: 30-236 ng/mL
5 years: 39-250 ng/mL
6 years: 47-275 ng/mL
7 years: 54-312 ng/mL
8 years: 61-356 ng/mL
9 years: 67-405 ng/mL
10 years: 73-456 ng/mL
11 years: 79-506 ng/mL
12 years: 84-551 ng/mL
13 years: 90-589 ng/mL
14 years: 95-618 ng/mL
15 years: 99-633 ng/mL
16 years: 104-633 ng/mL
17 years: 107-615 ng/mL
18-22 years: 91-442 ng/mL
23-25 years: 66-346 ng/mL
26-30 years: 60-329 ng/mL
31-35 years: 54-310 ng/mL
36-40 years: 48-292 ng/mL
41-45 years: 44-275 ng/mL
46-50 years: 40-259 ng/mL
51-55 years: 37-245 ng/mL
56-60 years: 34-232 ng/mL
61-65 years: 33-220 ng/mL
66-70 years: 32-209 ng/mL
71-75 years: 32-200 ng/mL
76-80 years: 33-192 ng/mL
81-85 years: 33-185 ng/mL
86-90 years: 33-179 ng/mL
91+ years: 32-173 ng/mL

Females:
0-11 months: 14-192 ng/mL 1 year: 23-243 ng/mL
2 years: 28-256 ng/mL
3 years: 31-249 ng/mL
4 years: 33-237 ng/mL
5 years: 36-234 ng/mL
6 years: 39-246 ng/mL
7 years: 44-279 ng/mL
8 years: 51-334 ng/mL
9 years: 61-408 ng/mL
10 years: 73-495 ng/mL
11 years: 88-585 ng/mL
12 years: 104-665 ng/mL
13 years: 120-719 ng/mL
14 years: 136-729 ng/mL
15 years: 147-691 ng/mL
16 years: 153-611 ng/mL
17 years: 149-509 ng/mL
18-22 years: 85-370 ng/mL
23-25 years: 73-320 ng/mL
26-30 years: 66-303 ng/mL
31-35 years: 59-279 ng/mL
36-40 years: 54-258 ng/mL
41-45 years: 49-240 ng/mL
46-50 years: 44-227 ng/mL
51-55 years: 40-217 ng/mL
56-60 years: 37-208 ng/mL
61-65 years: 35-201 ng/mL
66-70 years: 34-194 ng/mL
71-75 years: 34-187 ng/mL
76-80 years: 34-182 ng/mL
81-85 years: 34-177 ng/mL
86-90 years: 33-175 ng/mL
91+ years: 25-179 ng/mL