course upgrade -- fix serious bug where it shows a lot of NaN's
course upgrade -- fix serious bug where it shows a lot of NaN's

sagemathinc/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc