condition mean min max ZT0-3 5.87697 5.87697 5.87697 ZT4-7 4.8119 4.8119 4.8119 ZT8-11 4.49721 4.49721 4.49721 ZT12-15 4.27825 4.27825 4.27825 ZT16-19 5.662555 5.662555 5.662555 ZT20-23 4.441385 4.441385 4.441385