1 in 5000 is the lowest you can get on the NHS report now. May have been different previously. So your score could be 1 in 10,000 but they would always report it as a max of 1 in 5,000. Its a bit like how if you get your folic acid blood test done by the NHS if its any higher than 20 it just says 20, it wont say 50 for example cause its just their labs cutoff.
I had one in 10,000 with my first and now 1 in 5,000. Thought it was my age but reassured to hear it has changed
I think the scoring changed so 1 in 5000 is now the lowest reported score