Audit committees for the largest companies continue to raise the bar on what they voluntarily say in their reports about their responsibility for and oversight of the external audit.

The latest report from EY Center for Board Matters found 2015 proxy statements of Fortune 100 companies “continued and expanded even further” the voluntary audit-related disclosures that EY began studying in 2012. Several factors seem to be driving audit committees to say more, says EY, including requests from investors. “Policymakers and other stakeholders also have been active in calling for attention to the important role of audit committees and promoting consideration of greater transparency around how audit committees carry out their responsibilities,” EY wrote in its report.

The Securities and Exchange Commission is looking for feedback on its earliest ideas on where audit committees should perhaps expand their disclosures to investors. The Public Company Accounting Oversight Board, meanwhile, is exploring various possible expansion of disclosures by auditors, including expanded audit reports and disclosure of the engagement partner and other outside participants in public company audits.

In its analysis, EY says 21 percent of audit committees disclosed in 2015 they are responsible for negotiating audit fees, up from 18 percent in 2014 and 9 percent in 2013. In 2012, not a single audit committee in EY’s Fortune 100 sample made such a disclosure. In 2015, 9 percent of audit committees explained a reason for a change in the audit fee paid to external auditors, compared with 3 percent in 2012. All but 20 percent said they consider non-audit fees and services when assessing auditor independence, but fewer than 11 percent addressed that topic in 2012.

Audit committees are saying a great deal more about their assessment of the external auditor, with 58 percent making a positive assertion that their choice of external auditor is in the best interests of the company and/or its shareholders, while only 3 percent made such a statement in 2012. A majority of audit committees, at 61 percent, said, they are involved in selecting the lead partner on the engagement, a topic addressed by 47 percent in 2012 and none at all in 2012. Nearly 40 percent of audit committees disclosed factors they considered in assessing the external auditors’ qualifications and work quality in 2015, up from 17 percent in 2012.

Audit committees still have little to say, however, about the topics they discussed with their external auditor. Only 8 percent addressed that issue in 2015. and that figure has held study since the start of EY’s analysis with 2012 disclosures.