condition mean min max ZT0-3 18.3077 18.3077 18.3077 ZT4-7 15.783999999999999 15.783999999999999 15.783999999999999 ZT8-11 15.136849999999999 15.136849999999999 15.136849999999999 ZT12-15 19.90465 19.90465 19.90465 ZT16-19 21.346049999999998 21.346049999999998 21.346049999999998 ZT20-23 18.3009 18.3009 18.3009