Time	0.0	1.5	3.0	4.5	6.0	7.5	9.0	10.5	12.0	13.5	15.0	16.5	18.0
Conc 	21.0 	19.0 	15.0 	12.5 	10.5 	9.0 	7.8 	7.0 	6.2 	5.7 	5.4 	5.0 	4.7