http://opinions.kycourts.net/sc/2016-SC-000530-TG.pdf

Today, the Kentucky Supreme Court issued its opinion regarding the statutory “Look Back” rule. The practical effect of this opinion is this: prior to the state legislature passing this law, the state of Kentucky punished people more harshly if they were arrested for multiple DUIs within a 5 year period. After the 5 year period, any convictions that were older than 5 years could not be used against you to enhance the penalties for a subsequent offense. Under the new law, the enhancement period is now 10 years so even if it has been over 5 years since your last offense,  any new offense will be enhanced. The defense bar challenged the law primarily using contract law and ex post facto but obviously lost. Read the opinion.