Finding Total of all Values in a Column [RNG]

I'm working on a program that prints out a table filled with randomly-generated integers. Most of the logic is relatively straightforward and works pretty well. One thing I'd like to do is to add up and print out total values for each column, as well as the final total of all the values in the table. I've searched around trying to find an answer but have had no luck with figuring it out.

rowNbr = 7; // ROW CONTROLS
colNbr = 5; //COLUMN CONTROLS

rpt01 = String.format("%0" + (colNbr-1) + "d", 0).replace("0",dash); //Redefine rpt01
colBld = String.format("|---------------|%s\n",rpt01); //Redefine colBld

String cnrTxt = "First Quarter";

System.out.printf(colBld);
System.out.printf("|%-15s",cnrTxt);

for(int i = 1; i < colNbr; i = i++){ //Open for loop (columns)

String regTxt = "Region " + i++;

System.out.printf("|%-10s",regTxt);

} //End for

System.out.printf("|\n");

//Initialize array

int sales[] = new int[100];
  int idx = 0;
for(int i = 1; i <= rowNbr-3; i++){

String prodTxt = "Product " + i;

System.out.printf(colBld);
System.out.printf("|%-15s|",prodTxt);


for(int j = 0; j < colNbr-1; j++){ //Open for loop (columns 2)

    sales[idx] = (int)(Math.random() * 16 + 1);
    System.out.printf("%-10d|",sales[idx]);
    idx++;
} //End for

System.out.printf("\n");

} //End for

int totalNbr = 0; //Placeholder zero
int regNbr = 0; //Placeholder zero

String totalTxt = "Final Total: ";
String regTxt = "Region Totals";

System.out.printf(colBld);
System.out.printf("|%-15s|%-10s|\n",regTxt,regNbr); 
System.out.printf(colBld);
System.out.printf("|%s%s\n",totalTxt,totalNbr); 
System.out.printf(colBld);

Here is what the code currently looks like once run:

|---------------|----------|----------|----------|----------|
|First Quarter  |Region 1  |Region 2  |Region 3  |Region 4  |
|---------------|----------|----------|----------|----------|
|Product 1      |2         |10        |3         |1         |
|---------------|----------|----------|----------|----------|
|Product 2      |15        |15        |7         |16        |
|---------------|----------|----------|----------|----------|
|Product 3      |15        |13        |7         |9         |
|---------------|----------|----------|----------|----------|
|Product 4      |4         |14        |11        |11        |
|---------------|----------|----------|----------|----------|
|Region Totals  |0         |
|---------------|----------|----------|----------|----------|
|Final total: 0
|---------------|----------|----------|----------|----------|

Honestly have no idea where to even begin with this. All help is appreciated; thanks for your time!