(a) The number of teachers eligible for sabbatical leave that may be allowed under AS 14.20.280 — 14.20.350 is as follows: (1) not more than one-half of one percent of the total number of teachers from all borough and city school districts and regional educational attendance areas may be on state-supported sabbatical leave in any year;
(2) any number of teachers may be on sabbatical leave at school district or personal expense.
(b) A teacher on state-supported sabbatical leave is entitled to one-half of base salary to be paid by the department.
(c) A teacher on sabbatical leave at district expense is entitled to an amount of salary to be determined by the school board.