condition mean min max ZT0-3 1.43646 1.43646 1.43646 ZT4-7 0.6924265000000001 0.6924265000000001 0.6924265000000001 ZT8-11 7.465135 7.465135 7.465135 ZT12-15 27.14835 27.14835 27.14835 ZT16-19 12.603033333333332 12.603033333333332 12.603033333333332 ZT20-23 5.02237 5.02237 5.02237