Surplus shall include:
(a) Revenue receipts made available by the lapsing of unencumbered appropriation balances at the beginning of the budget year;
(b) Receipts from unanticipated miscellaneous revenues of the preceding fiscal year;
(c) Receipts from anticipated miscellaneous revenues of the preceding fiscal year in excess of the estimates in the budget;
(d) Receipts during the previous fiscal year from taxes or liens against which a complete reserve has been established.