Every time I update the program I noticed that update size is not more than 5-6 mb.
then why the full program update?
5-6 mb is the prices update. You can disable it by going to the menu "Tools->Settings" and unticking all the checkboxes that display the prices.
No displayed prices => no prices updates.
Perhaps,You could use patch file that contains only the update.
I plan to make incremental updates in the future. The download size should be much smaller.
I've tried several patch programs, but they don't give good enough results.
I have to create my own system, that's why it'll take me some time to add this feature...