condition mean min max ZT0-3 14.753725 14.4689 15.03855 ZT4-7 27.47005 27.47005 27.47005 ZT8-11 18.48005 18.48005 18.48005 ZT12-15 0 0 0 ZT16-19 12.036100000000001 12.036100000000001 12.036100000000001 ZT20-23 13.17605 13.17605 13.17605