Idea of Ratings Icon
It's a logo representing an upwards rating trend. There are two "pages", stacked one above the other, with the bottom sheet stacked slightly to the right and under the top sheet, with a an arrow pointing up and to the right, with a small downward trend in the middle of the top sheet.
This page shows the different variations of the Ratings from an Icons8 icon pack. Feel free to resize and recolor the icon, and then download the icon in PNG format for free.