The Houses of the Oireachtas was ranked fifth lowest of 31 parliaments in an international league table measuring the number of acts it passed last year.
Some 67 bills were passed in the Dáil and Seanad compared to 289 in the Polish parliament and 229 in the Netherlands.
Only the Westminster parliament (36 bills), the Greek parliament (37), the Spanish parliament (61 bills) and the Scottish parliament with (13 bills) trailed the Dáil and Seanad, according to the Oireachtas Commission's annual report for 2015.
The report, published this evening, shows the total cost of the Oireachtas Banking Inquiry was €6.2m.
The inquiry held 95 public hearings and took evidence from 131 witnesses.
The total cost of running the Oireachtas in 2015 came to €107m, which was almost €5m less than had been budgeted for.
The Dáil had the highest number of questions per member, averaging 319 each compared to an average of 37 parliamentary questions in 27 other parliaments internationally.
The pay and pensions of elected members cost more than €30m while expenses and allowances, including those of former members, accounted for €9.6m.
A total of €87,000 was spent on travel by Oireachtas Committees.
The Dáil sat for 118 days last year while the Seanad met 106 times.