condition mean min max ZT0-3 8.5082575 7.335735 9.680779999999999 ZT4-7 11.058900000000001 11.058900000000001 11.058900000000001 ZT8-11 12.90905 12.90905 12.90905 ZT12-15 0 0 0 ZT16-19 18.549950000000003 18.549950000000003 18.549950000000003 ZT20-23 16.2905 16.2905 16.2905