What do we enter on Turbo Tax on the Massachusetts Taxable IRA Distributions page?

Both of us received Traditional IRA distributions in 2018 and TT is asking "To determine the taxable amount for Massachusetts, enter the following information: 1) Other Contributions previously taxed by MA  2) Total Distributions received in previous years"

What do we enter for #1?
I'm guessing for #2 we have to add up the distributions we received in 2015 and 2016? Is that correct?   When we leave it blank TT actually lets us continue right along and will even allow us to submit our taxes but I think that might be a bad thing to do.
thanks!