Dean Jones says:

"Perhaps you are right; perhaps I have overestimated your abilities.  How about TWELVE independent study undergraduate research projects per academic year (two-semester period)?

1.  I accept your generous offer; supervising twelve independent study projects per year sounds much better than sixteen.

2.  I can meet you partway:  I will agree to three per academic year.

3.  I can meet you partway:  I will agree to four per academic year. 

4.  I can meet you partway:  I will agree to six per academic year.