What percentage of Sonja and payments have gone to paying interest?

To determine the percentage of Sonja's payments that have gone to paying interest, you would need to divide the total amount paid in interest by the total payments made, then multiply by 100. For example, if Sonja paid $1,000 in interest out of $5,000 in total payments, the calculation would be ($1,000 / $5,000) × 100, resulting in 20%. Without specific figures, it's impossible to provide an exact percentage.