condition mean min max ZT0-3 11.731186 11.731186 11.731186 ZT4-7 12.421568 12.421568 12.421568 ZT8-11 12.3068085 12.3068085 12.3068085 ZT12-15 10.9545925 10.9545925 10.9545925 ZT16-19 10.936225499999999 10.936225499999999 10.936225499999999 ZT20-23 10.53472 10.53472 10.53472