condition mean min max ZT0-3 14.104825 12.7639 15.44575 ZT4-7 13.31775 13.31775 13.31775 ZT8-11 37.965050000000005 37.965050000000005 37.965050000000005 ZT12-15 0 0 0 ZT16-19 37.92785 37.92785 37.92785 ZT20-23 27.111 27.111 27.111