condition mean min max ZT0-3 5.049355 4.774565 5.324145 ZT4-7 6.870744999999999 6.870744999999999 6.870744999999999 ZT8-11 7.63439 7.63439 7.63439 ZT12-15 0 0 0 ZT16-19 8.08905 8.08905 8.08905 ZT20-23 5.9232700000000005 5.9232700000000005 5.9232700000000005