A workshop's safety papers for two years sit oddly together: injuries entered in the accident book fell from 60 to 45, while the workshop's own measure of injuries for every lakh hours worked rose from 3 to 4.5. Which of the following, if true, best explains both records?

Sixty injuries in twenty lakh hours is three for every lakh; forty-five in ten lakh hours is four and a half. Halving the hours worked is the one thing that lowers the count while lifting the rate, and it fits both figures to the decimal. Entering minor injuries for the first time would push the count up, not down. Guards on two benches would bring the count down but the rate with it. The quarterly inspection was in place through both years and moves neither figure.