That's very much a speed. It's a really slow speed, which is what was indicated with the sarcastic remark. 12 years/mile. So, I see rate (1 mile) and time (12

That's very much a speed. It's a really slow speed, which is what was indicated with the sarcastic remark. 12 years/mile. So, I see rate (1 mile) and time (12 years). If you want to REwrite this, you can say (1/12)mile/year. And that's also a speed.