Sally Statistics is implementing a system of statistical process control (SPC) charts in her factory in an effort to reduce the overall cost of scrapped product. The current cost of scrap is $X per month. If an 80% learning curve is expected in the use of the SPC charts to reduce the cost of scrap, what would the percentage reduction in monthly scrap cost be after the charts have been implemented for 12 months? (Hint: Model each month as a unit of production.)