Your non-Maryland income would be the income received while in Virginia, and any adjustments to income while in Virginia.
You may need to calculate this yourself. For instance:
You lived in MD from Jan-March (3 months) and VA from April -Dec (9 months). If your income in box 1 of your W2 is $10,000, $2,500 of that income is MD income and $7,500 is VA in come. [$10,000 divided by 12 months times 3 months and 9 months.]
Adjustments would be items like Student Loan interest paid, among other things, but it would be calculated the same way. For instance if you paid $500 in student loan interest throughout the year, $500 divided by 12 times 3 is $125. $125 would be allocated to MD and $375 to VA.