condition mean min max ZT0-3 7.03419 6.95214 7.1162399999999995 ZT4-7 7.2578499999999995 7.2578499999999995 7.2578499999999995 ZT8-11 8.172445 8.172445 8.172445 ZT12-15 0 0 0 ZT16-19 8.588470000000001 8.588470000000001 8.588470000000001 ZT20-23 8.936105000000001 8.936105000000001 8.936105000000001