8 8 4 (being approximately 2.32% and 0.48%, resp ectively, of the issued and outstanding common shares as of December 31, 2021). Of the 920,940 common shares issuable for outstanding awards, 822,046 common shares are issuable upon exercise of options and 98,894 are issuable upon vesting of RS Us (being approximat ely 0.43% and 0.05%, respectively, of the issued and outstanding common shares as of December 31, 2021). Annual Burn Rates: The Corporation’s annual burn rate under the 2018 Share Compensation Plan for each of the Corporat ion’s three most recently completed fiscal years are as follows: Burn Rates under the 2018 Share Compensation Plan 2019 2020 2021 Total number of annual awards granted under the 2018 Share Compensation Plan (1) 144,897 98,659 136,341 Weighted average number of common shares outstanding (2) 187,677,339 190,287,170 191,078,878 Burn rate 0.08% 0.05% 0.07% Notes (1) Includes options, performance-based RSUs and time-based RSUs. (2) Calculated in accordance with the CPA Canada Handbook: The weighted average number of common shares outstanding during the period is the number of common shares outstanding at the beginning of the applicable fiscal year, adjusted by the number of common shares bought back or issued during the applicable fiscal year multiplied by a time-weighting factor. The time-weighting factor is the number of days that the common shares are outstanding as a proportion of the total number of days in the applicable fiscal year. Amendments to the 2018 Share Compensation Plan: During the year ended December 31, 2021, no amendments were made to the 2018 Share Compensation Plan. 2018 Share Compensation Plan Summary The ensuing description is a summary of the 2018 Share Compensation Plan. Purpose: The stated purpose of the 2018 Sh are Compensation Plan is to advance the interests of the Corporation and its shareholders by: (a) ensuring that the interests of officers and employees are aligned with the success of the Corporation; (b) encouraging stock ownership by such persons; and (c) providing compensation opportunities to attract, retain and motivate such persons. Participants: Each officer and employee of the Corporation and its subsidiaries is eligible to participate in the 2018 Share Compensation Plan. Non-employee directors of the Corporation are not eligible to participat e in the 2018 Share Compensation Plan in respect of RSUs. Under the 2018 Share Comp ensation Plan, non-employee directors of the Corporation are eligible to participate in respect of options, however, only on a limited basis consistent with the guidelines of certain governance rating agencies. See “Restriction on the Award of RSUs and Gr ant of Options” in this section below.