condition mean min max ZT0-3 4.68886 4.68886 4.68886 ZT4-7 4.10661 4.10661 4.10661 ZT8-11 7.10398 7.10398 7.10398 ZT12-15 7.80699 7.80699 7.80699 ZT16-19 6.813535 6.813535 6.813535 ZT20-23 10.5876 10.5876 10.5876