condition mean min max ZT0-3 10.591016666666667 9.32189 12.116800000000001 ZT4-7 8.844560000000001 8.844560000000001 8.844560000000001 ZT8-11 8.895340000000001 8.895340000000001 8.895340000000001 ZT12-15 9.7011975 9.3091 10.093295 ZT16-19 9.279135 9.279135 9.279135 ZT20-23 10.921050000000001 10.921050000000001 10.921050000000001