....If your grades are already high, you don't NEED an upward trend...that is only important for students who struggled at first.
Most colleges don't give out A+'s. Most do give out A's or the equivalent. Having an A+ mean more than an A, when the person with the A at college X may easily have done better than the person with an A+ at college Y (since most schools set A as the highest possible grade) wouldn't make any sense.