3/4 of people don't leave the airport - can you provide a reference for that please? Assuming you are correct then, I would disagree that 5000 people a day is a small number! That'll only be a mere 175,000 then since January 1st.
Just watched Oliver Dowden on Question Time giving us the usual nonsense about the UK having real draconian measures already in place - you're having a laugh mate.