What are the terms of office for officers?

Officers serve a three‐year term beginning at the time of the installation at the session when elected and ending upon the installation of their successors at the next regular session of the National Council. Each person shall serve no more than three consecutive terms in any one or any combination of these offices. Regardless of the number of consecutive terms any person shall have served in any one or any combination of these offices other than that of President, such person shall be eligible for two consecutive terms as President.

Source:  2017 Board Slate Frequently Asked Questions (PDF)