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

r<=21 231 210.9 1.908 1.908
r=22 5092 5135.9 0.375 2.283
r=23 23119 23103.6 0.010 2.293
r=24 11558 11549.5 0.006 2.299

chi-square = 2.299 with df = 3; p-value = 0.512646