Stats: hide line items for "Views" and "Views Per Visitor" when that data is not available

[designsimply]

The "Views Per Visitor" calculation will be inaccurate for any data prior to 2012-12-03 when visitor stats were first made available.

Steps to reproduce:

1. Go to https://wordpress.com/stats/year for a blog started in 2011 or earlier
2. Hover over each bar in the graph for 2012 and earlier
3. Check to see if the "Views" and "Views Per Visitor" items are accurate

Result: "Visitors" is zero for 2011 and earlier and "Views Per Visitor" is skewed for 2012.

/hat tip stuwest for the original report ^{(also see wpcom mu-plugins/stats.php#6)}

[stale]

This issue has been marked as stale because it hasn't been updated in a while. It will be closed in a week. If you would like it to remain open, can you please comment below and see what you can do to get things moving with this issue? Thanks! 🙏