Hi HoosierDaddy 1874 has many varieties They used Obverses 6-7-8 and reverses G-H-I The Rare one is 1874H Obverse 7 reverse I rated R17 Then 1874H Obverse 6 Reverse I Rated R16. There is no breakdown other than the total mintage figures. I would guess most of the information is purely down to surviving coins that are still with us . Probably causes more questions than answers but I hope it helps.