condition mean min max ZT0-3 18.261237 18.261237 18.261237 ZT4-7 18.0791435 18.0791435 18.0791435 ZT8-11 16.1569015 16.1569015 16.1569015 ZT12-15 15.546265 15.546265 15.546265 ZT16-19 34.003607 34.003607 34.003607 ZT20-23 42.4468765 42.4468765 42.4468765