Forest & Tree Health
Your trees may be experiencing oak tatters, which is the result of herbicide drift from nearby agricultural fields.
I would encourage you to contact your local IDNR district forester for on-site technical assistance regarding the status of your 14-yr old tree planting.
IDNR District Forester Offices: https://www.dnr.illinois.gov/conservation/Forestry/Documents/DistrictForestersAugust2016.pdf
Best of luck!