condition mean min max ZT0-3 19.452754 19.452754 19.452754 ZT4-7 22.4415345 22.4415345 22.4415345 ZT8-11 22.4739315 22.4739315 22.4739315 ZT12-15 28.540332999999997 28.540332999999997 28.540332999999997 ZT16-19 17.9929745 17.9929745 17.9929745 ZT20-23 19.252441 19.252441 19.252441