condition mean min max ZT0-3 2.671004 0.983018 4.35899 ZT4-7 7.46544 7.46544 7.46544 ZT8-11 1.152004 1.152004 1.152004 ZT12-15 0 0 0 ZT16-19 3.061235 3.061235 3.061235 ZT20-23 0.97515 0.97515 0.97515