I have assumed that the Deputy's question relates to companies registered for tax in Ireland. Revenue's latest annual report on corporation tax was published on 25 June 2020. The Corporation Tax 2019 Payments and 2018 Returns report is based on Revenue's analysis of corporation tax payments in 2019 and corporation tax returns for 2018. The report includes details of companies registered for tax in Ireland, and Figure 7 on page 17 provides the number of companies that filed corporation tax returns in 2018, broken down by those reporting profits and liable to tax.
I am advised by Revenue that information is not available in respect of the mean and median tax payments for all companies. However the report provides extensive breakdowns of the available information concerning the amount of corporation tax paid by sector and by net payment amount, for example in Figure 3 and Table 5. The report is available at https://www.revenue.ie/en/corporate/documents/research/ct-analysis-2020.pdf .