Exempted or Non GST

I have opted regular scheme, but in previous year I don't have any sale or purchase so thats why I filed "Nil Return" upto 9 months, after that i started Potato Business which is Non-Gst product. so thats why I just put Sale and Purchase amount in 3B in Non/Exempted Category.
Now, I am continuing the business, so my quarry is, is it mandatory to show the exact amount of sales and purchase (which is submitted in 3B and 1) in my AY 2018-19 P&L A/C ????