Sorry flitefone but you are incorrect. At the moment there are 10 A320 based at Gatwick and 11 ex BMI A319 until March. A tenth G-GAT** will join them in April along with 4 more ex BMI A320 from LHR for the summer season. Other airbus from LHR also supplement at times to cover maintenance and at times to increase their utilisation. At the moment there are 10 Boeing 777 based but will be joined by an 11th when Gatwick-New York starts in May. The number of routes and flights has increased quite a bit in the last couple of years. You can always check by looking at the BA Jet Tracker at BA Source. Choose an aircraft and check where they are flying to and from. For Summer 2016 I stick by my total of 37.
Hope thius helps.
V.