condition mean min max ZT0-3 9.592538333333334 8.625415 10.42787 ZT4-7 7.741630000000001 7.741630000000001 7.741630000000001 ZT8-11 16.30445 16.30445 16.30445 ZT12-15 16.415275 15.725999999999999 17.10455 ZT16-19 19.01275 19.01275 19.01275 ZT20-23 14.1389 14.1389 14.1389