condition mean min max ZT0-3 415.546304 415.546304 415.546304 ZT4-7 250.5210545 250.5210545 250.5210545 ZT8-11 329.14962849999995 329.14962849999995 329.14962849999995 ZT12-15 717.814079 717.814079 717.814079 ZT16-19 594.8997139999999 594.8997139999999 594.8997139999999 ZT20-23 990.155588 990.155588 990.155588