condition mean min max ZT0-3 72.753299 72.753299 72.753299 ZT4-7 68.279954 68.279954 68.279954 ZT8-11 75.0910915 75.0910915 75.0910915 ZT12-15 62.938894499999996 62.938894499999996 62.938894499999996 ZT16-19 68.0857235 68.0857235 68.0857235 ZT20-23 64.695205 64.695205 64.695205