Admin-ajax.php killing site performance

Awesome plugin!

I’m not sure what the file below does but when I run a test on tools.pingdom.com, it takes almost 7 seconds to load and is throwing off my performance. Can you tell me how to resolve this?

Here is my performance test

http://elegantgraniteandmarble.com/wp/wp-admin/admin-ajax.php?action=wordfence_logHuman&hid=4C2801C2C195A6FE01E5A565E078CFE9&r=0.6446966035291553

https://wordpress.org/plugins/wordfence/