condition mean min max ZT0-3 15.805373333333334 9.96082 19.6115 ZT4-7 7.913485 7.913485 7.913485 ZT8-11 7.17167 7.17167 7.17167 ZT12-15 12.916025000000001 12.07385 13.7582 ZT16-19 14.7058 14.7058 14.7058 ZT20-23 21.7969 21.7969 21.7969