Hi,
 
I would like to display data in tabular format, as below:
 
Customer        Brand         Series     Year    January    February   March     April        May         June                     
Best Solution    Apple          S5          2015    $20,500     $15,300     $12,200    $16,000    $23,700     $28,900
Best Solution    Samsung     A6          2015    $21,000     $23,400     $15,440    $19,700    $25,300     $32,430
Best Solution    Apple          S5          2016    $18,200     $11,100     $18,900    $11,000    $24,600   

My question is what should I do to get my data in above layout. I will appreciate your help, please include code to show to how to write code and layout the fields to get the above output, as I am new to Apex and Visualforce. Thanks. 
 
Please see my apex class and Visualforce page. My apex class and vf page are producing results result as follows:
 
Customer          Brand          Series     Year    Month     Net Sale
Best Solution    Apple          S5          2015    1              $20,500  
Best Solution    Apple          S5          2015    2              $15,300
...
...
...
Best Solution    Apple          S5          2016    1              $18,200
...
...
Best Solution    Samsung     A6          2015    1              $21,000  
...
...
   
public with sharing class SaleSum {
 
    public Summary[ ] Summaries { get; set; }
 
 public SaleSum() {
        AggregateResult[ ] results = [
        Select Brand__c, CALENDAR_MONTH(Invoice__r.Invoice_Date__c) InvMn, CALENDAR_YEAR(Invoice__r.Invoice_Date__c) InvYr,
            SUM(Net_Amount_US__c) NetUS, SUM(Net_Amount_CDN__c) NetCDN, Invoice__r.Account__r.Currency_Id__c,     
            Invoice__r.Account__r.Customer_Id__c
        From Invoice_Line__c
        Group By Brand__c, CALENDAR_MONTH(Invoice__r.Invoice_Date__c), CALENDAR_YEAR(Invoice__r.Invoice_Date__c),
            Invoice__r.Account__r.Currency_Id__c, Invoice__r.Account__r.Customer_Id__c
        ];
       
        Summaries = new List<Summary>();
        for (AggregateResult gr : results) {
            Summaries.add(new Summary(gr));
        }
    }
 
    public class Summary {
        public Decimal NetUS { get; private set; }
        public Decimal NetCDN { get; private set; }
        public String Brand { get; private set; }
        public Integer InvMn { get; private set; }
        public integer InvYr { get; private set; }
        public String Curren { get; private set; }
        public String Customer { get; private set; }
       
   public Summary(AggregateResult gr) {
            NetUS = (Decimal) gr.get('NetUS');
            NetCDN = (Decimal) gr.get('NetCDN');
            Brand = (String) gr.get('Brand__c');
            InvMn = (Integer) gr.get('InvMn');
            InvYr = (Integer) gr.get('InvYr');
            Currency = (String) gr.get('Currency_Id__c');
            Customer = (String) gr.get('Customer_Id__c');
        }
    }
 
}
  <apex:page controller="TestController" title="Monthly Net Amount by Customer" >
    <apex:pageBlock title="Monthly Net Amount by Customer">
    <table>
    <tr>
            <td>Customer</td>
            <td>Brand</td>
            <td>Series</td>
            <td>Year</td>
            <td>Month</td>
            <td>Net Sale</td>
    </tr>
   
<apex:repeat value="{!Summaries}" var="summary">
           <tr>
                <td><apex:outputText value="{!summary.Name}"/></td>               
                <td><apex:outputText value="{!summary.Brand}"/></td>
                <td><apex:outputText value="{!summary.Series}"/></td>
                <td><apex:outputText value="{!summary.InvYr}"/></td>
                <td><apex:outputText value="{!summary.InvMn}"/></td>
                <td><apex:outputText value="{!summary.NetUS}" rendered="{!IF(summary.Curren='US',true,false)}"/></td>
                <td><apex:outputText value="{!summary.NetCDN}" rendered="{!IF(summary.Curren='CAD',true,false)}"/></td>
            </tr>
      </apex:repeat>
      </table>
    </apex:pageBlock>
</apex:page>