These are the statistics I've compiled for Memorial copper cents (1959-1982) I've pulled from circulation while coin roll hunting. 1959-P: 5 (0.3%) 1959-D: 11 (0.6%) 1960-P: 7 (0.4%) 1960-D: 15 (0.8%) 1961-P: 5 (0.3%) 1961-D: 10 (0.5%) 1962-P: 6 (0.3%) 1962-D: 14 (0.7%) 1963-P: 10 (0.5%) 1963-D: 13 (0.7%) 1964-P: 22 (1.2%) 1964-D: 34 (1.8%) 1965-P: 15 (0.8%) 1966-P: 20 (1.0%) 1967-P: 27 (1.4%) 1968-P: 24 (1.3%) 1968-D: 22 (1.2%) 1968-S: 1 (<0.1%) 1969-P: 12 (0.6%) 1969-D: 46 (2.4%) 1969-S: 6 (0.3%) 1970-P: 25 (1.3%) 1970-D: 28 (1.5%) 1970-S: 3 (0.2%) 1971-P: 21 (1.1%) 1971-D: 30 (1.6%) 1971-S: 3 (0.2%) 1972-P: 53 (2.8%) 1972-D: 23 (1.2%) 1972-S: 2 (0.1%) 1973-P: 71 (3.7%) 1973-D: 17 (0.9%) 1973-S: 1 (<0.1%) 1974-P: 95 (5.0%) 1974-D: 28 (1.5%) 1974-S: 2 (0.1%) 1975-P: 82 (4.3%) 1975-D: 24 (1.3%) 1976-P: 81 (4.2%) 1976-D: 24 (1.3%) 1977-P: 63 (3.3%) 1977-D: 24 (1.3%) 1978-P: 107 (5.6%) 1978-D: 33 (1.7%) 1979-P: 126 (6.6%) 1979-D: 27 (1.4%) 1980-P: 153 (8.0%) 1980-D: 21 (1.1%) 1981-P: 152 (8.0%) 1981-D: 42 (2.2%) 1982-P Large Date: 155 (8.1%) 1982-P Small Date: 25 (1.3%) 1982-D: 45 (2.4%) Total: 1911 (100.0%)
Very interesting. I've never figured these for pennies before. It really puts the incidence of the coins in perspective especially in light of the massive zinc mintages and huge attrition.
The percentages of each date and mint mark are based solely from within the distribution of Memorial copper cents. In other words zinc Memorial cents are entirely excluded from these statistics. As for the current distribution of Memorial zinc cents versus Memorial copper cents in circulation... I estimate it's about 15% copper. I haven't really kept exact count. Some rolls I get 10 or more and sometimes I get 5 or less, but I have noticed that I get about 7 or 8 copper cents (on average) per roll.
For many years there were about 20% coppers even as they were being hoarded. I figured this was because the zincs rot away so quickly that they couldn't accumulate even as the coppers were disappearing. The last couple years the percentage of coppers is finally beginning to drop. I'm guessing the mint will be swamped making 10 billion a year just to replace the rotting cents. At some point they'll have to put an end to the madness. This will happen very soon after there's a real economic recovery. They simply aren't going to want to produce 20 billion cents per year at a cost of about a billion dollars. It will be interesting to see what one cent coins survive after the mint recalls them. Nice AU 1966's will be somewhat uncommon but what about '84-D's? Most of these are already rotted away and the survivors are stained, gouged, ugly, and have oxide on them. Even mint set coins are a fright much of the time. The penny greatly outlived its usefulness. In a sane world it would have been discontinued in 1974 but then a lot of very interesting and potentially valuable coins would never have been made.
The number of copper cents per roll have seemed to come down in the last several years. I guess in large part because of what you stated: zinc production is very high. Then you also have the ongoing hoarding and destruction. Although it is difficult to determine how much of a factor those play. The zinc cents are garbage (as far as quality and durability). Especially the more recent shield reverse cents. As you also stated, they corrode quick and easy. They are not dense enough or something. And the copper jacket is too thin I think. It seems like the outer layer of the coin gets corroded too easily to last long in circulation. That actually could have been a good thing (from a collectors standpoint) if the mintage weren't so damn high, lol.