No more than twenty-five loans shall be made to eligible students during the first academic year this program is in effect. Twenty-five new loans may be made for the next three academic years until a total of one hundred loans are available. At least one-half of the loans shall be made to students from rural areas as defined in section 191.500. An eligible student may receive loans for each academic year he is pursuing a course of study directly leading to a degree of doctor of medicine or doctor of osteopathy, doctor of dental surgery, or doctor of dental medicine, or a bachelor of science degree in dental hygiene.