condition mean min max ZT0-3 0.9211021666666667 0.6005305000000001 1.268685 ZT4-7 0.693944 0.693944 0.693944 ZT8-11 1.1689455 1.1689455 1.1689455 ZT12-15 1.09657 1.04996 1.14318 ZT16-19 1.187795 1.187795 1.187795 ZT20-23 1.255605 1.255605 1.255605