condition mean min max ZT0-3 18.3239 18.3239 18.3239 ZT4-7 8.635064999999999 8.635064999999999 8.635064999999999 ZT8-11 21.988599999999998 21.988599999999998 21.988599999999998 ZT12-15 75.74025 75.74025 75.74025 ZT16-19 55.2391 55.2391 55.2391 ZT20-23 33.3134 33.3134 33.3134