You can refresh the data now by clicking ‘Refresh Immediately’ button or schedule the hourly or daily refresh by setting the time and clicking ‘Save’ button. You can cancel anytime by selecting ‘None’ for Frequency.
The percentage of the total accumulated number of questions as of today is calculated for each language per year. It shows how total number of the questions for each year has grown for each popular language. Looks R has accelerated the speed from 2014 while some languages like Perl and Objective C have slow down.