condition mean min max ZT0-3 10.571691 10.571691 10.571691 ZT4-7 14.132899 14.132899 14.132899 ZT8-11 11.834821999999999 11.834821999999999 11.834821999999999 ZT12-15 11.4755695 11.4755695 11.4755695 ZT16-19 11.926028 11.926028 11.926028 ZT20-23 15.033701 15.033701 15.033701