Drying rate question

[UpstateSC]

Hello, am getting close to finishing my small solar kiln, and I have a question about the max safe drying rate. The VT plans have a table for the max % loss per day that is safe. My question is about how this is calculated.

For example, if I have a board with 50% moisture and the max safe drying rate for the species is 5%, is it the calculation 50-5=45 or do I take 5% from 50 (50*95%=47.5)?

Thanks

[YellowHammer]

50% MC in the board -5% moisture content  =45% moisture content in the board. 

Next day, 45%-5%=40% and so on

Wood loses water fast when it has high moisture level, more slowly as moisture decreases. 

[UpstateSC]

Thanks. I figured it was that way but wanted to be sure.