Dynamic binding of mapping

The looping part of the visualforce

<apex:repeat value="{!opp90Map}" var="category" >     
        <td width="25%" valign="top">
    	<apex:pageBlock title="Top 90 Opp for {!category}">
     <apex:pageBlockTable value="{!opp90Map[category]}" var="opp">

and the map 

public Map<String, List<OppWrapper>> opp90Map {get; set; }  
        repNameList = new List<String>{'Brit', 'Emma', 'Jeanette', 'Kara'};
        opp90Map = new Map<String, List<oppWrapper>>();

Thanks,

public class GoalsOverView_Class {
    List<Opportunity> oppListStart;
    List<OppWrapper> opp90RepList;
    public List<OppWrapper> opp90AllList  { get; set; }
	public List<OppWrapper> opp90BritList  { get; set; }
    public List<OppWrapper> opp90EmmaList  { get; set; } 
	public List<OppWrapper> opp90JeanetteList  { get; set; } 
	public List<OppWrapper> opp90KaraList  { get; set; }     
    public List<String> repNameList {get; set; }
    public Map<String, List<OppWrapper>> opp90Map {get; set; }  
    OppWrapper newOpp;
    public aggregateResult aggOppTotal {get; set;}
    decimal closedTotal;
    public decimal variance {get; set;}
    Rep_Goal__c goal;
    Decimal goalTotal;
    public Decimal oppTotal {get; set;}
    String UserId;
    public String userName {get; set;}    
    public GoalsOverView_Class() {
        repNameList = new List<String>{'Brit', 'Emma', 'Jeanette', 'Kara'};
        opp90Map = new Map<String, List<oppWrapper>>();
        UserId = UserInfo.getUserId();
        oppTotal = 0;
        closedTotal = 0;
        goalTotal = 0;
        Variance = 0;
            // top 10 all
                oppListStart = [SELECT Name, StageName, Owner.firstname, Id, Amount, account.id, account.name, type, closedate FROM Opportunity 
                                                  WHERE StageName = 'A. Pending Sale' AND Amount != 0 AND Amount != NULL AND OwnerID=:userID
                                                  ORDER BY Amount DESC LIMIT 10]; 
                aggOppTotal = [SELECT Sum(Amount) TotalAmount FROM Opportunity WHERE StageName = 'W. Win' AND CloseDate = THIS_QUARTER];
                goal = [SELECT Total_Revenue__c, Total_Margin__c, User__R.firstname FROM Rep_goal__c WHERE User__c = :userID AND Goals__r.Start_Date_of_new_Quarter__c = THIS_QUARTER]; 
                goalTotal = goal.Total_Revenue__c;
                closedTotal = (Decimal)aggOppTotal.get('TotalAmount');
 				opp90AllList = generateOppList(oppListStart, goalTotal, closedTotal);
        for(String repName:repNameList) {
               oppListStart = [SELECT Name, StageName, Owner.firstname, Id, Amount, account.id, account.name, type, closedate FROM Opportunity 
                                                  WHERE  Owner.firstname =:repName
                                                  ORDER BY Amount DESC LIMIT 10]; 
                aggOppTotal = [SELECT Sum(Amount) TotalAmount FROM Opportunity WHERE StageName = 'W. Win' AND CloseDate = THIS_QUARTER];
                goal = [SELECT Total_Revenue__c, Total_Margin__c, User__R.firstname FROM Rep_goal__c WHERE User__c = :userID AND Goals__r.Start_Date_of_new_Quarter__c = THIS_QUARTER]; 
                goalTotal = goal.Total_Revenue__c;
                closedTotal = (Decimal)aggOppTotal.get('TotalAmount');
 				opp90RepList = generateOppList(oppListStart, goalTotal, closedTotal); 
            opp90Map.put(repName, opp90RepList);
        }
        // Brit
        opp90BritList = opp90Map.get('Brit');
        opp90EmmaList = opp90Map.get('Emma');
        opp90JeanetteList = opp90Map.get('Jeanette');
        opp90KaraList = opp90Map.get('Kara');
    }
    public List<OppWrapper> generateOppList(List<Opportunity> oppListStart, Decimal goalTotal, Decimal closedTotal) {
        	List<OppWrapper> oppList = new List<OppWrapper>();
            for (Opportunity opp:oppListStart) {
                system.debug('username=' + opp.owner.firstname);
                oppList.add(new OppWrapper(opp.owner.firstname, opp.account.name, opp.name,   opp.CloseDate, opp.Amount,  opp.id) );
                oppTotal = oppTotal + opp.amount;
            }
			if (goalTotal == NULL) {goalTotal = 0; } 
            if (closedTotal == NULL) {closedTotal = 0; }
        	oppList.add(new OppWrapper(NULL, NULL, 'Total Open Opp', NULL, OppTotal, NULL));
       		oppList.add(new OppWrapper(NULL, NULL, NULL, NULL, NULL, NULL));
       	    oppList.add(new OppWrapper(NULL, NULL, 'Total Closed Opp', NULL, closedTotal, NULL));
            oppList.add(new OppWrapper(NULL, NULL, 'Total Goal', NULL, goalTotal, NULL));
      	    return oppList;
    }
    public class OppWrapper {
        public String oppName {get; set; }
        public String acctName {get; set; }
        public String repName {get; set; }
        public Date closeDate {get; set; }
        public Decimal amount {get; set; }
        public String Id {get; set; }
        public  OppWrapper(String repName, String acctName, String oppName,  Date closedate, Decimal amount, String id) {
            this.oppName = oppName;
            this.closeDate = closeDate;
            this.amount = amount;
            this.id = id;
            this.acctname = acctName;
            this.repName = repName;
        }
    }  
}