private Number getUsePercentage(final IndexVolume volume) {
        final OptionalDouble optUsedPercent = volume.getCapacityInfo()
                .getUsedCapacityPercent();
        return optUsedPercent.isPresent()
                ? optUsedPercent.getAsDouble()
                : null;
    }
Add the columns to the table.
stroom-core-client/src/main/java/stroom/index/client/presenter/IndexVolumeStatusListPresenter.java