condition mean min max ZT0-3 10.163170000000001 10.163170000000001 10.163170000000001 ZT4-7 8.292235 8.292235 8.292235 ZT8-11 9.736225 9.736225 9.736225 ZT12-15 7.4615100000000005 7.4615100000000005 7.4615100000000005 ZT16-19 7.83572 7.83572 7.83572 ZT20-23 9.54312 9.54312 9.54312