N.C. Gen. Stat. § 136-93.2
The monetary value for existing trees removed and eligible for reimbursement to the Department as provided in G.S. 136-93 or G.S. 136-133.1 from State rights-of-way shall be determined on an annual basis by the Department. In determining the value of existing trees removed, the average cost per caliper inch shall be based on the lower value of either the average wholesale commercial nursery prices for hardwood and conifer plants, times a 2.5 multiplier for installation and warranty or the average cost per caliper inch for tree planting contracts let by the Department in the previous calendar year. The values shall be determined and published by the Department no later than December 15 of each year. The values established pursuant to this section shall be used in calculating the monetary value of trees removed from State rights-of-way beginning January 1 of each year. If the Department fails to publish changes in values by December 15, then the values existing on December 15 shall be applicable to existing trees removed and eligible for reimbursement for the following year.
N.C. Gen. Stat. § 136-93.2