condition mean min max ZT0-3 17.919956 17.919956 17.919956 ZT4-7 75.7986265 75.7986265 75.7986265 ZT8-11 96.016189 96.016189 96.016189 ZT12-15 23.479585999999998 23.479585999999998 23.479585999999998 ZT16-19 15.6672125 15.6672125 15.6672125 ZT20-23 8.381325 8.381325 8.381325