condition mean min max ZT0-3 6.89357 6.442775 7.344365 ZT4-7 6.99929 6.99929 6.99929 ZT8-11 17.64585 17.64585 17.64585 ZT12-15 0 0 0 ZT16-19 22.2018 22.2018 22.2018 ZT20-23 12.722100000000001 12.722100000000001 12.722100000000001