condition mean min max ZT0-3 5.6540675 4.710459999999999 6.597675 ZT4-7 3.6964699999999997 3.6964699999999997 3.6964699999999997 ZT8-11 3.8498 3.8498 3.8498 ZT12-15 0 0 0 ZT16-19 8.192205 8.192205 8.192205 ZT20-23 7.37546 7.37546 7.37546