condition mean min max ZT0-3 9.316157 9.316157 9.316157 ZT4-7 8.9542345 8.9542345 8.9542345 ZT8-11 8.9043885 8.9043885 8.9043885 ZT12-15 9.7064345 9.7064345 9.7064345 ZT16-19 8.7027805 8.7027805 8.7027805 ZT20-23 9.288756 9.288756 9.288756