condition mean min max ZT0-3 2.6568025 2.6079 2.705705 ZT4-7 2.8144400000000003 2.8144400000000003 2.8144400000000003 ZT8-11 2.075775 2.075775 2.075775 ZT12-15 0 0 0 ZT16-19 3.354715 3.354715 3.354715 ZT20-23 3.4344099999999997 3.4344099999999997 3.4344099999999997