condition mean min max ZT0-3 354.246705 354.246705 354.246705 ZT4-7 418.856827 418.856827 418.856827 ZT8-11 487.089161 487.089161 487.089161 ZT12-15 504.7593915 504.7593915 504.7593915 ZT16-19 454.3176205 454.3176205 454.3176205 ZT20-23 309.21738949999997 309.21738949999997 309.21738949999997