condition mean min max ZT0-3 3.38815 3.38815 3.38815 ZT4-7 2.43534 2.43534 2.43534 ZT8-11 3.3738 3.3738 3.3738 ZT12-15 4.1301 4.1301 4.1301 ZT16-19 4.485315 4.485315 4.485315 ZT20-23 3.4238150000000003 3.4238150000000003 3.4238150000000003