condition mean min max ZT0-3 23.763025 19.75265 27.773400000000002 ZT4-7 6.839815 6.839815 6.839815 ZT8-11 7.979369999999999 7.979369999999999 7.979369999999999 ZT12-15 0 0 0 ZT16-19 11.267205 11.267205 11.267205 ZT20-23 18.50375 18.50375 18.50375