abcdefhiklmnopqrstuvwxyzPercentage of Violations Receiving Enforcement0%20%40%60%80%100%2005200620072008200920102011201220132014201520166547559459391,01484588862263335596643241018121130110103118000002001572072321913331,3991,3201,281918611349808Violations Receiving Informal Enforcement ActionsViolations Receiving a Compliance ActionViolations Receiving Penalty ActionsViolations Receiving No EnforcementNumber of Violations Receiving the HighestLevel of Enforcement by Year, Region 4