condition mean min max ZT0-3 2.6857191666666664 0.9105325 3.880655 ZT4-7 1.4223400000000002 1.4223400000000002 1.4223400000000002 ZT8-11 4.13467 4.13467 4.13467 ZT12-15 4.3108325 3.852935 4.76873 ZT16-19 7.175655 7.175655 7.175655 ZT20-23 4.640145 4.640145 4.640145