condition mean min max ZT0-3 5.736538333333333 5.157275 6.331284999999999 ZT4-7 5.550485 5.550485 5.550485 ZT8-11 6.847315 6.847315 6.847315 ZT12-15 13.074 12.27045 13.87755 ZT16-19 12.2986 12.2986 12.2986 ZT20-23 10.187470000000001 10.187470000000001 10.187470000000001