condition mean min max ZT0-3 2.336975 1.68021 2.779565 ZT4-7 1.99802 1.99802 1.99802 ZT8-11 4.510935 4.510935 4.510935 ZT12-15 6.1570825000000005 3.7038699999999998 8.610295 ZT16-19 5.59009 5.59009 5.59009 ZT20-23 5.05129 5.05129 5.05129