Roth 457 rollover to Roth IRA. 1099-R question on box 5.

I rolled over my Roth 457 to a Roth IRA last year. I had money taken out of my paycheck after taxes to contribute to the Roth 457 during my contributions.

 

I received a 1099-R and the only thing filled out is the gross distribution amount in box 1 and distribution code G in box 7. I am confused why box 5 is left blank. Is this box for contributions that would have been made outside of my paycheck from me?

 

IRS instructions and TurboTax explain it in a way that seems like my contributions amount should be in box 5.