condition mean min max ZT0-3 5.160571666666667 3.6203450000000004 5.96915 ZT4-7 8.460425 8.460425 8.460425 ZT8-11 4.36372 4.36372 4.36372 ZT12-15 5.3546625 5.0004349999999995 5.70889 ZT16-19 6.006185 6.006185 6.006185 ZT20-23 4.354515 4.354515 4.354515