final private GATKReport createGATKReport(){
final GATKReport report = new GATKReport();
report.addTable("ReadLengthDistribution", "Table of read length distributions", 1 + (readGroupsLocation.isEmpty() ? 1 : readGroupsLocation.size()));
final GATKReportTable tableReport = report.getTable("ReadLengthDistribution");
tableReport.addColumn("readLength");
if (readGroupsLocation.isEmpty()){
tableReport.addColumn("SINGLE_SAMPLE");
int rowIndex = 0;
for (Integer length : table.keySet()){