condition mean min max ZT0-3 2.142625 2.142625 2.142625 ZT4-7 1.519115 1.519115 1.519115 ZT8-11 3.470905 3.470905 3.470905 ZT12-15 3.202635 3.202635 3.202635 ZT16-19 6.57395 6.57395 6.57395 ZT20-23 1.50277 1.50277 1.50277