A district road office reports two findings for the same four years: the share of road accidents involving an e-rickshaw rose from 4 in every hundred to 11 in every hundred, while the number of accidents involving an e-rickshaw was much the same in the fourth year as in the first. Which of the following, if true, best accounts for both findings together?

If the e-rickshaw count held steady while its share nearly trebled, the total it is a share of must have shrunk to roughly four-elevenths of its old size — that is, to about a third. Nothing else will square the two findings. More e-rickshaws on the roads would explain a rise in their accidents, which did not happen, and leaves the share untouched; a licensing rule and a new entry form might alter the count, but neither holds the count still while lifting the share.