condition mean min max ZT0-3 6.123236666666666 4.70928 7.537193333333333 ZT4-7 4.1101600000000005 4.1101600000000005 4.1101600000000005 ZT8-11 4.91525 4.91525 4.91525 ZT12-15 8.534794999999999 5.87969 11.1899 ZT16-19 11.8733 11.8733 11.8733 ZT20-23 8.0996 8.0996 8.0996