condition mean min max ZT0-3 14.7667 14.7667 14.7667 ZT4-7 11.06813 11.06813 11.06813 ZT8-11 8.69342 8.69342 8.69342 ZT12-15 13.4362 13.4362 13.4362 ZT16-19 11.895299999999999 11.895299999999999 11.895299999999999 ZT20-23 14.914200000000001 14.914200000000001 14.914200000000001