condition mean min max ZT0-3 5.49789 5.49789 5.49789 ZT4-7 4.3022 4.3022 4.3022 ZT8-11 7.21981 7.21981 7.21981 ZT12-15 8.512755 8.512755 8.512755 ZT16-19 9.535815 9.535815 9.535815 ZT20-23 6.4407700000000006 6.4407700000000006 6.4407700000000006