I have rows of inventory data sorted by NBV. I would like to return 50 total rows of data by pulling 20 rows where the NBV is >=$500 and 30 rows where the NBV is <$500; however, I have some instances where I don't have a total of 20 rows >=$500. How would I be able to fill in the missing rows of >=$500 with extra <$500 rows so that I will always return the desired 50 total rows?