ICANN tracks the general health of the DNS ecosystem and related ecosystems. The data is updated irregularly, but historic data is available. The collected data covers eight major topics:

M1: inaccuracy of Whois Data
M2: Domain Name Abuse
M3: DNS Root Traffic Analysis
M4: DNS Recursive Server Analysis
M5: Recursive Resolver Integrity
M6: IANA registries for DNS parameters
M7: DNSSEC Deployment.
M8: DNS Authoritative Servers Analysis

Each topic has too many sub categories to list here.