condition mean min max ZT0-3 24.135344 24.135344 24.135344 ZT4-7 15.7899905 15.7899905 15.7899905 ZT8-11 14.944937 14.944937 14.944937 ZT12-15 13.458234000000001 13.458234000000001 13.458234000000001 ZT16-19 10.404938 10.404938 10.404938 ZT20-23 9.838588000000001 9.838588000000001 9.838588000000001