A new auditor is assigned to the allowance for doubtful accounts and perform the

A new auditor is assigned to the allowance for doubtful accounts and perform the analytical procedures detailed in the chart. There have been no significant changes during the year in either the client’s credit policies or customer base. Are there any auditing concerns about adjusting the allowance for doubtful accounts based on the information shown below?
2018 2017 2016
Client/Industry Client/Industry Client/Industry
Allowance/AR 8.3/7.2 8.5/7.4 8.3/7.4
Days AR Outstanding 32.4/23.8 28.6/25.1 28.3/24.7