Hi Gill, first of all congratulations! It’s definitely an achievement worth including on your writing CV and in a cover letter when submitting to agents. It’s worth noting that if there are multiple rounds it might be best to wait until the competition ends before sharing the results with an agent as you never know how far you might go.
We couldn’t quite find the results on their website so we can’t comment on the number of finalists vs the number of entrants, but if you do have any questions about the number of entrants I would consider reaching out to the organisers and see if they are happy to give you more details.
Katie