While it can be limited in terms of granular and specific insight, existing sources can provide some forms of data quickly and cheaply. Data gathered by other researchers is available online, or you may already be gathering your own data which you can use for benchmarking and evaluation.
Assess the information available in your existing records, such as employment data, information on funding recipients or creative commissions. You can also track your budget allocations to culturally diverse programming.
If you gather information during email signups about language or cultural identity, you can track changes in your mailing list over time, or use digital analytics for insight into where your online audiences are located. You can also monitor your reviews, for example in community-language media and social networks
For more general information, data like census information from the UK Office for National Statistics or the Australian Bureau of Statistics can give you insight into the demographics of your local area (for example if there are a large number of, say, Bengali speakers in your neighbourhood).