hey... 85% of statistics are made up on the spot!
to prevent that cold-air/deflation problem, i use a small MEC lightweight dry bag as my sleeping bag's stuff sack. since the sack is waterproof and airtight, i wrap the opening of it around the valve of the thermarest, hold it tight, and squeeze it to pump air into the thermarest. then, it's a balancing act of continuing to squeeze (cuz it's not a perfect fit) and using the other hand to hold on to the seal and turn the valve at the same time. it takes some practice at home first, but it works for me.
i used to blow into my mattress too, but eventually the mattress foam/fabric delaminated, i'm guessing due to mildew buildup inside from the moisture in my breath. now, i avoid blowing into the mattress whenever possible.