Final answer:
The necessary information to determine the percentage of real estate agents who specialized in property management in 2016 from the National Association of REALTORS® is not provided, so the question cannot be accurately answered without additional data.
Step-by-step explanation:
The National Association of REALTORS® provides comprehensive data about various aspects of the real estate profession, including specialization areas of its members. However, the reference information provided does not include the percentage of real estate agents who specialized in property management in 2016.
As such, it's not possible to confidently answer this question without access to the specific data from the National Association of REALTORS® on this topic. For accurate and current statistics, it's recommended to consult the latest reports or data releases from the National Association of REALTORS® directly.