condition mean min max ZT0-3 10.147737 10.147737 10.147737 ZT4-7 9.343897 9.343897 9.343897 ZT8-11 8.5676975 8.5676975 8.5676975 ZT12-15 9.751436 9.751436 9.751436 ZT16-19 9.3904385 9.3904385 9.3904385 ZT20-23 8.7471245 8.7471245 8.7471245