You got the Standard Deduction. One of you was over 65. You get an extra 1,300 for each spouse 65 or older. 24,000+1,300=25,300
For 2018 the standard deduction amounts are:
Single 12,000 + 1,600 for 65 and over
HOH 18,000 + 1,600 for 65 and over
Joint 24,000 + 1,300 for each 65 and over
Married filing Separate 12,000 + 1,300 for 65 and over
