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

r<=28 197 211.4 0.983 0.983
r=29 5158 5134.0 0.112 1.095
r=30 23081 23103.0 0.021 1.116
r=31 11564 11551.5 0.013 1.130

chi-square = 1.130 with df = 3; p-value = 0.770