Tax Credits Question

Can someone please help me with this? Please see below: Last year - You filed as Single. - Your total income was $45,626. - You took the Standard Deduction of $13,850. - Your taxable income was $31,776. - Your total tax before credits was $3,593. - You claimed $584 in tax credits. - Your total payments were $3,770 from W-2 and 1099 withholdings. - You received a refund of $761. This year - Your filing status is still Single. - Your total income is $40,136. - You are taking the Standard Deduction of $14,600. - Your taxable income is $25,536. - Your total tax before credits is $2,942. - You did not claim any tax credits. - Your total payments are $2,675 from your W-2 withholdings. - You have a balance due of $267. Last year, I claimed $584 in tax credits, but 0 this year. I'm thinking that I did something wrong this year. How do I identify what the $584 credit consisted of for last year? Is there a specific place on last year's return that I can look? This year's income was about $5,500 less than last years. Could I have overlooked something? Thanks in advance.