How often are estimates to be submitted in relation to other expenditure?
Based on the context provided, estimates are to be submitted in relation to other expenditure every year. This is because the text states that "So much of the said estimates as relates to other expenditure shall be submitted in the form of demands for grants to the House of the People." This sentence implies that these estimates and grants need to be reviewed and approved by the House of the People on an annual basis, which suggests that this process occurs every year.