condition mean min max ZT0-3 5.022345 5.022345 5.022345 ZT4-7 2.529265 2.529265 2.529265 ZT8-11 2.777925 2.777925 2.777925 ZT12-15 4.89436 4.89436 4.89436 ZT16-19 8.790995 8.790995 8.790995 ZT20-23 8.197425 8.197425 8.197425