condition mean min max ZT0-3 0.9364871666666668 0.495907 1.313865 ZT4-7 0.439766 0.439766 0.439766 ZT8-11 0.5983430000000001 0.5983430000000001 0.5983430000000001 ZT12-15 0.46047775 0.4228985 0.49805699999999997 ZT16-19 0.6844325 0.6844325 0.6844325 ZT20-23 0.6675975 0.6675975 0.6675975