Article: The FA permitted artificial turf (3G) pitches in all rounds of the competition from the 2014–15 edition and beyond. Under the 2015-16 rules, the pitch must be of FIFA One Star quality, or Two Star for ties if they involve one of the 92 professional clubs. This followed approval two years previously for their use in the qualifying rounds only - if a team with a 3G pitch progressed to the competition proper, they had to switch their tie to the ground of another eligible entrant with a natural grass pitch. Having been strong proponents of the surface, the first match in the proper rounds to be played on a 3G surface was a televised first round replay at Maidstone United's Gallagher Stadium on 20 November 2015.

Question: How many professional clubs are there?
92