condition mean min max ZT0-3 23.546325 23.546325 23.546325 ZT4-7 13.008394000000001 13.008394000000001 13.008394000000001 ZT8-11 8.292091 8.292091 8.292091 ZT12-15 8.8997385 8.8997385 8.8997385 ZT16-19 7.5245485 7.5245485 7.5245485 ZT20-23 7.294249499999999 7.294249499999999 7.294249499999999