clag on Adding units to Google Gauge: ie. %, hPa, °C

I'd like to be able to add units to the bottom value on google gauges. I have tried:

var formatter = new google.visualization.NumberFormat({pattern: "#'%'"});

but cannot get it to work.

also:

var formatter = new google.visualization.NumberFormat(
{suffix: '%',pattern:'#'}
);
formatter.format(data,1);

Could anyone help me?