Well, of that 70% G-E, it depends on how much is "excellent" and how much is just "good"? Also how much is the "very very very really really really excellent" that Illinois and Indiana touted last year, when I would`ve called northern Iowa a disapionting year, last year.
I guess most of us that do a 70mph crop tour assess a nice green, good stand, not visibly weedy, <2% yellow patches or drown outs or burnup corn field as "good to excellent". But every field has a story, one guy didn`t apply N and was depending on sidedressing, however went on vacay during that 1 week window to get that done with his rig, well that combined with wet weather it was too big but he did it anyway, he must`ve sidedressed the maximum+ #50 because that crappy, yellow hiphigh corn turned a dark dark green in just a few days and shot up. It looks "good to excellent", but it was starved during the plants` ear size determination growth, so I would say the jury is out on exactly how it will actually yield. Have to keep in mind that isn`t normal opperating for most "G-E" corn fields though.
I`m at a disadvantage in judging this crop because, I have only seen good to excellent corn in my limited travels, as far as I would be concerned it`s all good to excellent except pictures that I see on the internet. But the internet is the same place that tells me there are "beautiful single women 5 miles away that want to date you" too ..so 
I`m just kidding, I know there`s a band down south from Kansas to Ohio that`s been terribly wet and I am sorry for you guys. Just divining the information that I read, I would guess the corn crop to be nationally 160 at this time.
There is a patch of poor corn in north Iowa, some hippie organic farmers have some late planted corn long way from tassel and on the other half of their farm is some 2014 corn that they still need to pick...they have done the same thing year after year and they keep going so who am I to judge.
