condition mean min max ZT0-3 2.2319424999999997 2.0874499999999996 2.376435 ZT4-7 3.197935 3.197935 3.197935 ZT8-11 3.598705 3.598705 3.598705 ZT12-15 0 0 0 ZT16-19 3.59489 3.59489 3.59489 ZT20-23 3.4116150000000003 3.4116150000000003 3.4116150000000003