The Compendium of Caraka 8.3.32

8.3.32

ādvādaśāt syāt prasṛtābhivṛddhirāṣṭādaśād dvādaśataḥ paraṃ syuḥ/
&āsaptatestadvihitaṃ pramāṇamataḥ paraṃ ṣoḍaśavadvidheyam//

up to twelve years; there should be an increase of one prasṛti [per year] up to eighteen; beyond twelve, there are [increases],
up to seventy years, that prescribed measure holds; beyond that, it should be administered as for a sixteen-year-old.