If you want to legally use published statistics on a t-shirt for a print on demand business, you must ensure that you have the necessary rights to use the statistics. This may involve obtaining permission from the owner of the statistics or ensuring that the statistics are in the public domain.

Assuming that the statistics are in the public domain, you can use them on a t-shirt for a print on demand business without seeking permission. However, it is still important to cite your sources to avoid any potential legal issues. Here are some steps you can take to properly cite your sources:

Determine the source of the statistics, such as a government agency or research organization.

Locate the specific publication or report that contains the statistics.

Include the name of the source and the title of the publication or report on your t-shirt design. For example, you could use the following format: "Source: [Name of Source], [Title of Publication/Report], [Date of Publication]."

If possible, include a link to the source of the statistics on your t-shirt design or on your online store where the t-shirt is sold. This can help customers verify the accuracy of the statistics and ensure that you are citing your sources correctly.

By properly citing your sources, you can help ensure that you are using published statistics legally and avoid any potential legal issues. It's always a good idea to consult with a lawyer if you have any questions about the legality of using published statistics on a t-shirt or other product for commercial purposes.