A few highlights stand out from this summary by the BBC:

• Not much wall has been built. Over-hyped and under-delivered
• Interesting seasonality to apprehensions, particularly in the past
• 2017 and 2018 apprehensions not really much different from recent past and a lot lower than a decade ago

Trump wall: How much has he actually built?

What happened to President Trump's long-promised wall? How much of it got built? And how effective has it been?

www.bbc.com