A psychology professor assigns letter grades on a test according to the following scheme.

A: Top 13% of scores

B: Scores below the top 13% and above the bottom 57%

C: Scores below the top 43% and above the bottom 22%

D: Scores below the top 78% and above the bottom 8%

F: Bottom 8% of scores

Scores on the test are normally distributed with a mean of 71 and a standard deviation of 8.1. Find the numerical limits for a C grade. Round your answers to the nearest whole number, if necessary.