Auditor tenure seemed to register as somewhat proportional to the size of the company. While the weighted average auditor tenure for public companies was 21 years, companies with more than $25 billion in revenues reported keeping the same auditor an average of 50 years, and the smallest companies in the survey -- with revenues of less than $25 million -- had auditors with tenure of less than 10 years.

Asked how often companies put their audit engagements out for bid, a clear majority of companies in the survey reported doing so only when they decided to switch auditors. This was more pronounced (89%) for accelerated companies -- those with more than $700 million in revenues -- while 57% of U.S. non-accelerated filers put audits out for bid only when deciding to switch. Some 60% of private companies gave this answer.

The 62% of public companies reporting centralized operations paid an average $2.9 million for their annual financial statement audits, while those with decentralized operations paid $5.3 million.