Each school year, the state must pay a district for each child or student screened by the district according to the requirements of section 121A.17. The amount of state aid for each child or student screened shall be: (1) $75 for a child screened at age three; (2) $50 for a child screened at age four; (3) $40 for a child screened at age five or six prior to kindergarten; and (4) $30 for a student screened within 30 days after first enrolling in a public school kindergarten if the student has not previously been screened according to the requirements of section 121A.17. If this amount of aid is insufficient, the district may permanently transfer from the general fund an amount that, when added to the aid, is sufficient. Developmental screening aid shall not be paid for any student who is screened more than 30 days after the first day of attendance at a public school kindergarten, except if a student transfers to another public school kindergarten within 30 days after first enrolling in a Minnesota public school kindergarten program. In this case, if the student has not been screened, the district to which the student transfers may receive developmental screening aid for screening that student when the screening is performed within 30 days of the transfer date.