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

r<=28 207 211.4 0.092 0.092
r=29 5122 5134.0 0.028 0.120
r=30 23164 23103.0 0.161 0.281
r=31 11507 11551.5 0.172 0.453

chi-square = 0.453 with df = 3; p-value = 0.929