RANK OBSERVED EXPECTED (O-E)^2/E SUM

r<=21 218 210.9 0.236 0.236
r=22 5057 5135.9 1.212 1.448
r=23 23251 23103.6 0.940 2.388
r=24 11474 11549.5 0.494 2.882

chi-square = 2.882 with df = 3; p-value = 0.410147