The Competition in Contracting Act of 1984 requires that the Comptroller General (i.e. the GAO or Government Accountability Office) report to Congress each instance in which a federal agency did not fully implement one of its recommendations in connection with a bid protest decided in the prior fiscal year and each instances in which a final decision in a protest was not rendered within 100 days after the protest was filed.
The GAO just published its Fiscal Year 2017 Bid Protest Annual Report to Congress and reported that there were no such instances in Fiscal Year 2017. The report also provided summary level data concerning the overall protest filings for the year and shows comparative data from previous years.
The number of bid protest cases filed dropped by almost 200 cases from Fiscal Year 2016. Perhaps one reason for this drop was the suspension of a prolific filer (see GAO Suspends Firm From Filing Bid Protests for One Year).
GAO issued 581 decisions (sustained and denied) of which 99 were sustained. That represents a sustention rate of only 17 percent - down from 23 percent the previous fiscal year. The effectiveness rate which measures a protestor obtaining some form of relief from the agency, either as a result of voluntary agency corrective action or the GAO sustaining the protest was 47 percent, up slightly from 46 percent the previous year.
The number of ADR (Alternative Disputes Resolution) cases totaled 81. The success rate for ADR cases was 90 percent. Seems like ADR might be the way to go with bid protests as the chances for success is almost double that of a formal GAO hearing.
You can read the full GAO report here.