Unless they are making a complete horlicks of their CAA statistics submission (which I guess is a possibility) then May's CAA figures do not make for happy reading.
Flybe Q400 fleet has 10,024 passengers uplifted across 654 stage flights so an average of 15.3 passengers per flight. Looking at the data another way, they had 18,694,000 seat km available and the report states 3,677,000 used which gives you the same answer - 19.6% load factor.