condition mean min max ZT0-3 4.362155 4.362155 4.362155 ZT4-7 2.7962350000000002 2.7962350000000002 2.7962350000000002 ZT8-11 9.52567 9.52567 9.52567 ZT12-15 16.46955 16.46955 16.46955 ZT16-19 13.333549999999999 13.333549999999999 13.333549999999999 ZT20-23 6.565875 6.565875 6.565875