Lies, Damned Lies & Statistics.
You would probably be in the 40% if you were American, which is still a large proportion, and also remember it's dollars, not pounds, exchange rate isn't as good as it once was, but it's not parity yet.
The headline sensationalises the statistics a bit, there's not much difference between the two platforms by the look of things.
It story also looks to contradict itself, in the first paragraph claiming -
"iPhone users pay more than $100 a month, according to a survey in the US by Consumer Intelligence Research. Meanwhile, a shade over half of polled Android users spent less"
and then in the last paragraph -
"54 per cent fall into the greater-than-$100-a-month category."
Maybe I'm interpretting it incorrectly, but those two statments look to be contradictory.