condition mean min max ZT0-3 6.670846666666667 1.43092 10.07815 ZT4-7 1.27943 1.27943 1.27943 ZT8-11 4.24398 4.24398 4.24398 ZT12-15 4.641484999999999 4.26987 5.0131 ZT16-19 9.363285 9.363285 9.363285 ZT20-23 8.800740000000001 8.800740000000001 8.800740000000001