Since then Las Vegas visitor traffic recovered to new record highs.
However, in 2018, visitor traffic declined 0.2% compared to 2017, but was still 7.5% above the pre-recession peak.
Convention attendance declined 2.2% in 2018 from the record high in 2017. Here is the data from the Las Vegas Convention and Visitors Authority.
The blue bars are annual visitor traffic (left scale), and the red line is convention attendance (right scale).
Historically, declines in Las Vegas visitor traffic have been associated with economic weakness, so the declines in 2017 and 2018 are a little concerning for the Vegas area.