condition mean min max ZT0-3 21.734875 19.5995 23.87025 ZT4-7 26.08025 26.08025 26.08025 ZT8-11 23.6573 23.6573 23.6573 ZT12-15 0 0 0 ZT16-19 18.03745 18.03745 18.03745 ZT20-23 23.596600000000002 23.596600000000002 23.596600000000002