You're not calculating your rate to compare to others - just to see your own progress and if you want to figure out when you're financially independent. So what matters is how fast your savings grow in comparison to your expenses. In your example, if you start with $100,000 getting 12% dividend returns ($1000 per month) and $5000 in salary... and you only spend $1000.
Year 0 $100,000 spending $12,000
Year 1 $160,000 spending $12,000
Year 2 $227,200 spending $12,000
Year 3 $302,464 spending $12,000 - You're FI!
Now you probably still want to figure out a percentage. I would say it's 83.3% because salary is just one source of income. Investment returns, freelance and any other way you earn money increases your financial engine.