Without data, there is no way to measure progress or even establish a baseline.
Except for a brief period in the Bill Clinton administration when James Lee Witt, FEMA director (it was a cabinet-level position back then) brought an emphasis — mitigation has been a red-headed stepchild in the emergency management family. In 1995-96, when I first became more involved in the subject area, I had emergency managers tell me that the word "mitigation" sounded like "litigation," which showed the depth of their knowledge of the subject area. Twenty-two years later, I'm not so sure we have made much progress.
See this Pew report, Natural Disaster Mitigation Spending Not Comprehensively Tracked. The subject title is a good summary of the findings. The bottom line is that we as a community of emergency managers are not good at collecting data and thus cannot tell our story. Not that mitigation would be the first chapter in any story written by emergency managers. We'd rather talk about disaster preparedness and the sexy topic of disaster response. Mitigation is only a priority when funding becomes available "post-disaster" when FEMA opens the checkbook.
Back to the topic of performance measurement — it is hard to do in our emergency management world, but we could at least count the dollars being expended. Money loosely translates into effort. Little money, little effort! It takes the episodic post-disaster mitigation funding to really open the federal purse. Without the federal funding — there would be little mitigation being done. There are few isolated state examples called out in the report, but they are few in number.
See the chart below that depicts the lopsided distribution of funds between pre- and post-disaster mitigation.