The Company maintains a restricted stock incentive plan for the purpose of attracting and retaining officers, employees, and non-employee board members. Share awards generally vest in equal annual installments over a three to ten year period from date of issuance. Non-vested shares have voting rights and are eligible for any dividends paid to common shares. The Company recognized compensation cost for these fixed awards over the service vesting period, which represents the requisite service period, using the straight-line method. Prior to our IPO, the value of non-vested shares was calculated based on the offering price of the shares in the most recent private placement offering of $20.00, adjusted for stock dividends since granted and assumed selling costs, which management believed approximated fair market value as of the date of grant. Upon our IPO, the value of non-vested shares granted is generally calculated based on the closing price of our common stock on the date of the grant. During our Annual Stockholders meeting, held on May 26, 2022, the Company's 2017 Incentive Award Plan was amended to increase the available shares for issuance from 1.1 million to 2.5 million.

The non-vested restricted shares outstanding as of December 31, 2022 will vest over the next one to five years.

Share-based compensation expense for the years ended December 31, 2022 and 2021 was approximately $1.2 million and $1.6 million , respectively. As of December 31, 2022 and 2021 , future unrecognized stock compensation related to unvested shares totaled approximately $1.5 million and $1.6 million, respectively.