condition mean min max ZT0-3 9.799947 9.799947 9.799947 ZT4-7 9.554773 9.554773 9.554773 ZT8-11 8.4492225 8.4492225 8.4492225 ZT12-15 7.8572205 7.8572205 7.8572205 ZT16-19 8.850525 8.850525 8.850525 ZT20-23 9.039771 9.039771 9.039771