Artificial intelligence (AI) models are increasingly autonomous in decision-making, making pursuing responsible AI more critical than ever. Responsible AI (RAI) is defined by its commitment to transparency, privacy, safety, inclusiveness, and fairness. But while the principles of RAI are clear and shared, RAI practices and auditing mechanisms are still incipient. A key challenge is establishing metrics and benchmarks that define performance goals aligned with RAI principles. This paper describes how the ITACA AI auditing platform developed by this http URL tackles demographic benchmarking when auditing AI recommender systems. To this end, we describe a Demographic Benchmarking Framework designed to measure the populations potentially impacted by specific AI models. The framework serves us as auditors as it allows us to not just measure but establish acceptability ranges for specific performance indicators, which we share with the developers of the systems we audit so they can build balanced training datasets and measure and monitor fairness throughout the AI lifecycle. It is also a valuable resource for policymakers in drafting effective and enforceable regulations. Our approach integrates socio-demographic insights directly into AI systems, reducing bias and improving overall performance. The main contributions of this study include:1. Defining control datasets tailored to specific demographics so they can be used in model training; 2. Comparing the overall population with those impacted by the deployed model to identify discrepancies and account for structural bias; and 3. Quantifying drift in different scenarios continuously and as a post-market monitoring mechanism.