condition mean min max ZT0-3 7.736084999999999 7.736084999999999 7.736084999999999 ZT4-7 3.974625 3.974625 3.974625 ZT8-11 6.427239999999999 6.427239999999999 6.427239999999999 ZT12-15 6.654695 6.654695 6.654695 ZT16-19 13.8047 13.8047 13.8047 ZT20-23 9.19282 9.19282 9.19282