getting constant totals from a table

Hi, am using android API. I have a table in the backendless console, name contributions. In that table there is a column for amount. My problem is, when i get the total amount of all the columns, i keeps on changing. Here’s the code

//get the total contribution amount
Backendless.Persistence.of(Contributions.class).find(new AsyncCallback<BackendlessCollection<Contributions>>() {
    @Override
    public void handleResponse(BackendlessCollection<Contributions> contributionsBackendlessCollection) {
        contributions = contributionsBackendlessCollection;
        int cSize = contributions.getData().size();
        //sum up the contributed amount
        for (int i = 0; i < cSize; i++) {
            contributedAmount += contributions.getData().get(i).getContribution_amount();

        }
        balanceAmount = requiredAmount - contributedAmount;
        Log.d("Balance is ;;;; ", "" + balanceAmount);
        actualContributedField.setText(String.valueOf(contributedAmount));
        balanceField.setText(String.valueOf(balanceAmount));
        Log.d("Size of data", String.valueOf(cSize) + " Total is " + contributedAmount);
    }

    @Override
    public void handleFault(BackendlessFault backendlessFault) {
        Toast.makeText(SummaryActivity.this, backendlessFault.getMessage(), Toast.LENGTH_SHORT).show();

    }
});

the amount keeps on changing whenever i refresh that. How can i make the pulled amount not to change?? Because its supposed to be constant amount from the saved data.

Unless there are new data objects in the Contributions table, the API will return the same data set every time. If you get different results, you need to check with a debugger where the difference comes from. I cannot think of any reason other than the returned data set is different every time (new objects are being created)