condition mean min max ZT0-3 14.942825 14.50095 15.384699999999999 ZT4-7 9.619019999999999 9.619019999999999 9.619019999999999 ZT8-11 7.828215 7.828215 7.828215 ZT12-15 0 0 0 ZT16-19 12.63851 12.63851 12.63851 ZT20-23 20.5138 20.5138 20.5138