This is very different, some species have only a few eggs, to 20, for example ornaticauda or parvulus, others like Harvey or tweediei can make 30-50 eggs, my opalius had more than 70 eggs, the rest floats in the form about 60 juveniles with me in the aquarium. This also depends on the age and from exercise.
Animals which have spawned several times with me and are older than younger animals lay more eggs, plus it also depends on how well harmonize the pairs, sometimes helping a change of partners around the eggs to increase the amount.
And of course, good varied food.