On January 1, 2018, David Corp. grants options that permit key executives to acquire 32 million of the company's $1 par common shares within the next 8 years, but not before December 31, 2021 (the vesting date). The exercise price is $27 per share. The fair value of the options, estimated by an appropriate option-pricing model, is $7 per option.

David Corp.'s policy is to estimate option forfeitures. Originally, a forfeiture rate of 3% was expected. During 2020, the third year, David Corp. revised its estimate of forfeitures from 3% to 7%.

What are the journal entry for 2018, 2019, 2020 and 2021 to record compensation expense, considering expected forfeitures.