Homebuyer traffic nationwide tumbled in May, according to the latest Campbell/Inside Mortgage Finance Monthly Survey of Real Estate Market Conditions. Most of the decline was attributable to first-time homebuyers who sharply reduced their home shopping last month. The survey's first-time homebuyer traffic index, which measures home shopping activity on a scale of 1 to 100, registered an anemic 35.1 in May. This was down from an index of 63.5 in April. Since September 2009, the index had never been below 50, which represents a flat, or neutral, condition in home purchase activity.