67 years of age with Roth withdrawal in '16. Should total NET Roth Contributions before 2016 include the Conversion amount from Traditional IRA to a Roth in 1998.

I converted and paid taxes in '98, '99,'00 and '01.  After that I made several non deductible contributions.  Is it correct to total all of these to get the correct amount for NET Contributions prior to 2016?  Or is this number even needed? I am 67 and only withdrew a small amount.