10 Invoice Restriction on Starter package - good but not practicable

As a low volume sales invoice generator a normal year would be 22 invoice per annum and abnormal would be 33 invoice per annum. The monthly restriction for me creates an admin problem. As I need to generate at the same time 11 invoices twice a year! Understand these limits as you pay far less on the starter, but maybe it could look at annual use as well so come up with a forumula that looks at the past three months or something. I am probably a rare case and this is likly to be a low priority or be considered not worth it. But may be there are others out there who also find this restriction just a bit annoying.