Your AGI determines the percentage of the contributions you made during the year that you may claim,
up to the maximum of $150 ($300 if married filing jointly).
Credit percentage from Table 12 of Pub OR-17 (2020)
AGI
$0- 30,000 100%
30,001-70,000 50%
70,001- 100,000 25%
100,00- 250,000 10%
250,001+ 5%
