BILLBOARD RANKS MADONNA'S 40 BIGGEST HITS ON THEIR CHARTS

Madonna has been a staple on the Billboard charts for 30 years now, so it's no surprise the chart makers would work up a list of her biggest hits upon the release of her latest album, MDNA. Billboard explains how they rank the hits:"The ranking is based on actual performance on the weekly Billboard Hot 100 chart. Songs are ranked based on an inverse point system, with weeks at No. 1 earning the