condition mean min max ZT0-3 7.26269 7.26269 7.26269 ZT4-7 7.494595 7.494595 7.494595 ZT8-11 5.31851 5.31851 5.31851 ZT12-15 6.68502 6.68502 6.68502 ZT16-19 7.607894999999999 7.607894999999999 7.607894999999999 ZT20-23 6.84628 6.84628 6.84628