condition mean min max ZT0-3 3.4094575000000003 3.11483 3.704085 ZT4-7 1.983815 1.983815 1.983815 ZT8-11 1.877745 1.877745 1.877745 ZT12-15 0 0 0 ZT16-19 1.78562 1.78562 1.78562 ZT20-23 1.722525 1.722525 1.722525