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

r<=28 216 211.4 0.099 0.099
r=29 5171 5134.0 0.267 0.366
r=30 23104 23103.0 0.000 0.366
r=31 11509 11551.5 0.157 0.522

chi-square = 0.522 with df = 3; p-value = 0.914