condition mean min max ZT0-3 8.4508175 8.168695 8.73294 ZT4-7 6.308260000000001 6.308260000000001 6.308260000000001 ZT8-11 7.50057 7.50057 7.50057 ZT12-15 0 0 0 ZT16-19 12.164200000000001 12.164200000000001 12.164200000000001 ZT20-23 10.95885 10.95885 10.95885