I need help understanding the numbers in red. Please explain from average time to % difference.

DATA TABLE Trial 1 Trial 2 Trial 3 Trial 4 Mass of pulley M, g 200 Mass of the first weight holder 50 mweight holder 1 (8) Mass of the weight, placed in the 20 40 60 80 weight holder 1 Am1 (8) Total ascending mass mi (8) 70 90 110 130 /Note: mi = mweight holder 1 + Ami/ Mass of the second weight holder 50 Mweight holder 2 (8) Mass of the weight, placed in the 30 50 70 90 weight holder 2 Am2 (8) Total descending mass m2 (8) 80 100 120 140 Note: m2 = mweight holder 2 + Am2/ Height of fall h 0.800 0.800 0.800 0.800 (m) Measurement 1 2.34 2.08 2.45 2.46 Measurement 2 2.15 2.46 2.64 2.57 Time of fall Measurement 3 1.98 2.25 2.24 2.62 Measurement 4 2.06 2.32 2.37 2.22 Measurement 5 2.04 2.14 2.48 2.61 Average time of fall t (s) 2.11 2.25 2.44 2.50 Keep 3-significant figures Theoretical acceleration ar from 0.392 0.338 0.297 0.265 (1)(m/s2), Keep 3-significant figures Measured acceleration am from 0.359 0.316 0.268 0.256 (2)(m/s2), Keep 3-significant figures % Difference: 8.78% 6.71% 10.3% 3.45% I am-aT |/[(am+an/]x100%