Microwave Versus Kettle

I did a quick experiment to find out which was more efficient for making a mug of tea: the kettle or the microwave.

Kettle: 3 KW
Microwave: 700 W

The kettle took almost exactly 1 minute to boil a mug of water.
The microwave took about 3 minutes.

So:
Energy used / Kettle = 3,000 Watts  x 1/60H= 50 WH

Energy used / Microwave =  700 Watts  x 3/60H = 35 WH

A saving of 15 watt-hours per mug.  I probably have about 8 mugs of tea or coffee per day, so a saving of 43.8 KWH / £6.25 per year on my current tariff.