condition mean min max ZT0-3 5.2515583333333336 3.934625 6.03883 ZT4-7 2.953615 2.953615 2.953615 ZT8-11 2.80591 2.80591 2.80591 ZT12-15 6.7153375 5.96874 7.461935 ZT16-19 7.0494 7.0494 7.0494 ZT20-23 8.534120000000001 8.534120000000001 8.534120000000001