condition mean min max ZT0-3 15.645144 15.645144 15.645144 ZT4-7 14.643377000000001 14.643377000000001 14.643377000000001 ZT8-11 14.9139465 14.9139465 14.9139465 ZT12-15 12.9358655 12.9358655 12.9358655 ZT16-19 13.591614 13.591614 13.591614 ZT20-23 12.45454 12.45454 12.45454