snowstorm a competitor questionmark, page-8

Tewks,

I can't figure the page 10 graph out completely, I was assuming the blue line was slag prices on the LH axis and the bubbles where the dates the different plants and deposits were originally built. If that was what they were saying then it only infers that the plant/deposit development costs have gone up each year and shows slag prices havent. I don't think they have actually plotted the capital costs.