The number of undergraduate students enrolled in the university of New Hampshire from domiciles outside the state in any year shall not exceed 25 percent of the maximum capacity for regular undergraduate students at the university as determined by the board of trustees. The limitation on out-of-state enrollment at the university may be suspended by vote of the board of trustees whenever the trustees find that such suspension benefits the state and the university without impairing the opportunity for qualified students of the state of New Hampshire to attend the university. However, any such suspension shall be made for not more than one year at a time but may be continued from year to year upon vote of said trustees. The limitation on out-of-state enrollment at the university of New Hampshire shall not apply to the following divisions of the university: Thompson school of applied science, summer school and graduate school. Nor shall the limitation apply to students attending the university under reciprocal agreements and contracts with other educational institutions.