Hovering over any chart will show an arrow in the top right hand corner.
Clicking the arrow will reveal a dropdown menu. Click “Share” to see options for downloading/exporting the visualization or data.
After clicking "Share" you will see a pop-up menu like the one below. Select the “Download” tab:
Once on the "Download" tab, you can choose how to download/export the data, either as an image of the current visualization (chart) or the underlying data set as an Excel or CSV format.