condition mean min max ZT0-3 10.148511666666666 7.164905 13.513584999999999 ZT4-7 7.91694 7.91694 7.91694 ZT8-11 9.65044 9.65044 9.65044 ZT12-15 14.859425 13.812999999999999 15.905850000000001 ZT16-19 8.89545 8.89545 8.89545 ZT20-23 9.022680000000001 9.022680000000001 9.022680000000001