condition mean min max ZT0-3 20.694437 20.694437 20.694437 ZT4-7 16.5360235 16.5360235 16.5360235 ZT8-11 16.7784925 16.7784925 16.7784925 ZT12-15 30.232587 30.232587 30.232587 ZT16-19 21.0400965 21.0400965 21.0400965 ZT20-23 26.335299000000003 26.335299000000003 26.335299000000003