condition mean min max ZT0-3 16.724351 16.724351 16.724351 ZT4-7 15.437649 15.437649 15.437649 ZT8-11 15.148495 15.148495 15.148495 ZT12-15 18.5434175 18.5434175 18.5434175 ZT16-19 16.3052735 16.3052735 16.3052735 ZT20-23 15.153159500000001 15.153159500000001 15.153159500000001