Nobody can answer about GSTR-9 Issue

Dear Sir,

We are exporters with LUT i.e., we export at Zero rated. But, in Annual Returns, for HSN code column 17, what should we put in Tax Rate because we have purchased at 18% Tax because this is the first time we are seeing Tax Rate at HSN column.  

I have shown as zero in all the products - is it correct or should we mention the purchase Tax.

Very urgent.

Regards