I've come up with three ideas to improve the chart's clarity:

• Add the npmx logo as a watermark to show the source of the image
  • The place of the logo can be changed the other place, for exapmle on the top?
  • I put to the bottom since there's a large empty space now
• Include more labels on the x-axis to make the time range easier to understand at a glance
  • though I'm not sure how difficult to implement
• Add horizontal grid lines to help users read the data points more accurately

/cc @graphieros