Take the net after tax figures as shown on back page (p.6) of NTMA Brochure 1 or 2 or 4 from the State Savings website which are as follows
……………………………………….………..….Net..........TOTAL
NTMA State Savings …………………..AER........ RETURN
3 year Savings Bonds ………....…………..3.23% 10.00%
4 year National Solidarity Bonds ……..3.31% 13.92%
5 ½ year Savings Certificates……………3.53% 21.00%
10 year National Solidarity Bonds….…3.95% 47.30%
Divide these figures by 73 and multiply by 100 (grossing up for 27% DIRT) to provide the following answer to your question
…………………………………………………….Gross…….TOTAL
NTMA State Savings …………….......AER.........RETURN
3 year Savings Bonds …………………......4.42% 13.70%
4 year National Solidarity Bonds ……..4.53% 19.07%
5 ½ year Savings Certificates……………4.84% 28.77%
10 year National Solidarity Bonds…....5.41% 64.79%