Figure 1.

Scatterplots of the log_e-transformed values of the quinine (QN), chloroquine (CQ), monodesethylamodiaquine (MdAQ), and artemisinin (ART) IC₅₀s between years. The straight line is the cut-off value for susceptibility to the products (here: 100 nM for CQ, 60 nM for AQ, 500 nM for QN and 15 nM for ART [4]). The means of each year are connected with a trend line. The box around each year distribution of values represent two standard deviation of the mean.