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

r<=28 219 211.4 0.272 0.272
r=29 5077 5134.0 0.633 0.905
r=30 23143 23103.0 0.069 0.974
r=31 11561 11551.5 0.008 0.982

chi-square = 0.982 with df = 3; p-value = 0.806