condition mean min max ZT0-3 3.5510025 3.261515 3.84049 ZT4-7 4.38955 4.38955 4.38955 ZT8-11 3.3248949999999997 3.3248949999999997 3.3248949999999997 ZT12-15 0 0 0 ZT16-19 2.4985600000000003 2.4985600000000003 2.4985600000000003 ZT20-23 3.2280699999999998 3.2280699999999998 3.2280699999999998