condition mean min max ZT0-3 6.423335 5.943875 6.902794999999999 ZT4-7 5.41791 5.41791 5.41791 ZT8-11 11.93995 11.93995 11.93995 ZT12-15 0 0 0 ZT16-19 12.58695 12.58695 12.58695 ZT20-23 9.559660000000001 9.559660000000001 9.559660000000001