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

r<=28 219 211.4 0.272 0.272
r=29 5165 5134.0 0.187 0.459
r=30 22967 23103.0 0.801 1.260
r=31 11649 11551.5 0.823 2.083

chi-square = 2.083 with df = 3; p-value = 0.555