condition mean min max ZT0-3 6.793333333 6.793333333 6.793333333 ZT4-7 7.0200000000000005 7.0200000000000005 7.0200000000000005 ZT8-11 8.575 8.575 8.575 ZT12-15 7.49 7.49 7.49 ZT16-19 4.861111111 4.861111111 4.861111111 ZT20-23 5.604444444666667 5.604444444666667 5.604444444666667