condition mean min max ZT0-3 9.532603333333334 7.31296 11.507200000000001 ZT4-7 15.577 15.577 15.577 ZT8-11 11.1666 11.1666 11.1666 ZT12-15 8.458455 7.4092 9.50771 ZT16-19 4.122075000000001 4.122075000000001 4.122075000000001 ZT20-23 4.70878 4.70878 4.70878