There are 950 menís tennis programs. They break down to 263 NCAA DI, 161 NCAA DII, 314 NCAA DIII, 92 NAIA and 120 NJCAA tennis programs.
For men there are 4.5 scholarships for NCAA DI and DII programs, 5 per team NAIA and up to 9 for NJCAA schools.
I guess if it were limited to American players you could go to TRN and look down 2850 players and find the cutoff for kids playing college tennis. Unfortunately there are not 2800 players listed for any graduating year.