condition mean min max ZT0-3 4.93306 4.40931 5.456810000000001 ZT4-7 5.84012 5.84012 5.84012 ZT8-11 13.94705 13.94705 13.94705 ZT12-15 0 0 0 ZT16-19 14.0084 14.0084 14.0084 ZT20-23 12.445450000000001 12.445450000000001 12.445450000000001