function runningFormatter(value, row, index) {
    return index;
}

function totalTextFormatter(data) {
    return 'Total';
}

function totalFormatter(data) {
    return data.length;
}

function sumFormatter(data) {
    field = this.field;
    return data.reduce(function(sum, row) { 
        return sum + (+row[field]);
    }, 0);
}

function avgFormatter(data) {
    return sumFormatter.call(this, data) / data.length;
}