condition mean min max ZT0-3 7.8308925 7.40626 8.255525 ZT4-7 5.943975 5.943975 5.943975 ZT8-11 3.2436249999999998 3.2436249999999998 3.2436249999999998 ZT12-15 0 0 0 ZT16-19 5.586589999999999 5.586589999999999 5.586589999999999 ZT20-23 8.03545 8.03545 8.03545