[ASTPP] invoice count not start as per configuration in company profile

I have a quick question for you. I noticed the invoice count has 000 or 0000 before the number. For example, invoice 101 has INV_000101 or INV_0000101. I was expecting something like INV_101.

I though this was a problem and I started looking through the database and the php code in astpp/application/modules/invoices/ but I couldn't figure it out.