1. There are exempted from the taxes imposed by this chapter the gross receipts from the sale of, and the storage, use or other consumption in a county of, tangible personal property used for the performance of a written contract entered into before July 1, 1967.
2. There are exempted from the additional taxes imposed by amendment to this chapter the gross receipts from the sale of, and the storage, use or other consumption in a county of, tangible personal property used for the performance of a written contract for construction entered into before May 1, 1981.
3. There are exempted from the additional taxes imposed by this chapter the gross receipts from the sale of, and the storage, use or other consumption in a county of, tangible personal property used for the performance of a written contract for construction of an improvement to real property, entered into before July 30, 1991, or for which a binding bid was submitted before that date if the bid was afterward accepted, if under the terms of the contract or bid the contract price or bid amount cannot be adjusted to reflect the imposition of the additional taxes.
4. There are exempted from the additional taxes imposed by amendment to this chapter the gross receipts from the sale of, and the storage, use or other consumption in a county of, tangible personal property used for the performance of a written contract entered into before July 1, 2009.