condition mean min max ZT0-3 21.637725 18.41955 24.8559 ZT4-7 8.914565 8.914565 8.914565 ZT8-11 5.674225 5.674225 5.674225 ZT12-15 0 0 0 ZT16-19 9.965340000000001 9.965340000000001 9.965340000000001 ZT20-23 14.619299999999999 14.619299999999999 14.619299999999999