If you really believe there were 51,000 at the game on Saturday you're in cloud cuckoo land
And not wanting to start an argument but you've said the attendance (I take it you mean official) was 53,000, then you say that there were probably 51,000 there but describe the missing 4,000 as "a few hundred"
Taking into account that 1,000 were Fulham seats that still, by your own estimation, leaves 3,000 missing which is over 5%. I would honestly estimate that is was more than 10%
I posted the highlights video and where it panned into the crowd at 37 minutes (and not the family stand), you could easily see that 1 in 10 seats in that block were empty