Well that's hard to say because it's a rolling survey of a couple thousand people. There is a separate survey by Action on Smoking and Health, published in the middle of this year, which came up with a similar figure that about two million, or one in five, smokers are using electronic cigarettes occasionally, and of those about 700,000, or just over one third, were using electronic cigarettes exclusively as a substitute for cigarettes. So they've given up smoking.
Our smoking statistics figures for 2013—some preliminary figures were released last week—show a drop in prevalence from 19.9 to 18.6, I think, which is the biggest year-on-year fall in prevalence over the last couple of decades.