condition mean min max ZT0-3 9.736958333333334 5.124835 12.4997 ZT4-7 3.61817 3.61817 3.61817 ZT8-11 4.040565 4.040565 4.040565 ZT12-15 5.3022025 4.218505 6.3858999999999995 ZT16-19 7.2854 7.2854 7.2854 ZT20-23 12.225850000000001 12.225850000000001 12.225850000000001