All motor vehicles owned by a school or educational institution and used principally for the purpose of transporting persons with disabilities or disabled students to or from such school or educational institution are exempted from any and all ad valorem taxes imposed by any tax jurisdiction in this state. The exemption provided for in this Code section shall apply only when such school or educational institution is qualified as an exempt organization under the United States Internal Revenue Code, Section 501(c)(3), as such section exists on January 1, 1984.