Start with the Auburn service area, not a population assumption
Auburn city is one municipality within Placer County. The available Census record identifies 13,768 residents for Auburn city in the 2020–2024 ACS 5-year estimates, with a margin of error of 35. It does not establish how many people seek legal help, where prospective clients begin, which practice areas they consider or how quickly they expect a response. It also does not describe the wider geography your firm may serve. Keep those distinctions clear when reviewing intake performance. A resident of Auburn city, a person elsewhere in Placer County and a household are not interchangeable measurement units.
Recommended approach
Use Auburn and Placer County as the initial geographic frame for an intake review, then compare it with the locations your firm actually serves. Bring real inquiry records, referral paths and matter categories to the consultation. Do not use population as a substitute for lead volume or a reason to automate every interaction.
