Marginal Abatement Cost Curve for China

The chart plots the carbon price in US Dollars (market exchange rate) against Gt of Co2 abated for China using the results from seven of the EMF-22 models. This is not really a cost curve as it includes data for different time periods and model scenarios. I've been struggling to model this data over the last 10 days or so on and off. But this is actually the first time I've plotted the data like