Using the same data as OARC's Root Zone Trends, we also have simple graphs showing the count and percentage of TLDs (including any IANA testbed TLDs) signed with DNSSEC. More correctly, this is the number of TLDs with one or more DS records published in the root zone. There may be some signed TLDs that haven't published DS records, and there may be some TLDs publishing bad DS records.
These graphs are updated daily.
(click for full size)