condition mean min max ZT0-3 317.847441 317.847441 317.847441 ZT4-7 341.232084 341.232084 341.232084 ZT8-11 389.424364 389.424364 389.424364 ZT12-15 431.576711 431.576711 431.576711 ZT16-19 359.9741375 359.9741375 359.9741375 ZT20-23 326.067833 326.067833 326.067833