condition mean min max ZT0-3 6.506805 5.220245 7.793365 ZT4-7 10.331150000000001 10.331150000000001 10.331150000000001 ZT8-11 11.5237 11.5237 11.5237 ZT12-15 0 0 0 ZT16-19 12.8308 12.8308 12.8308 ZT20-23 12.477599999999999 12.477599999999999 12.477599999999999