condition mean min max ZT0-3 16.45215 16.4472 16.4571 ZT4-7 18.8479 18.8479 18.8479 ZT8-11 19.37655 19.37655 19.37655 ZT12-15 0 0 0 ZT16-19 19.5379 19.5379 19.5379 ZT20-23 17.1355 17.1355 17.1355