condition mean min max ZT0-3 3.084801421 2.2844346140000003 3.885168228 ZT4-7 3.21973454725 2.7093444115 3.7301246829999997 ZT8-11 4.602573345 3.22788597 5.97726072 ZT12-15 7.489289351 6.787915222 8.19066348 ZT16-19 8.55182848175 8.4380166045 8.665640359000001 ZT20-23 8.84210642375 8.827102018 8.8571108295