They didn't, they've sold more than 25 million in the first three quarters (9 months) of this calendar year:
first quarter,
second quarter,
third quarter (Apple's fiscal year is a quarter off the calendar year, so links are to appropriate quarters and so the total does not include the 7.33 million iPads sold in their first fiscal quarter).
There weren't. I haven't researched the total Android tablets actually sold to consumers this year, but the numbers you're likely quoting are from reports like those from Strategy Analytics, which are
Android tablets shipped to retailers, not tablets actually sold. Apple's numbers are iPads actually sold to humans.
Assuming those numbers were correct -- which they weren't -- you're ignoring sales of iPads in the 4th calendar quarter. Apple sold 9.25 million last quarter, and the coming quarter is, as Christmas buying dictates, their annual best. Based on year-over-year sales increase percentages for the last two quarters (average of 174.5%), they're on track to sell more than 16 million iPads in this last quarter of the year; even working off the incorrect 6:15 starting ratio, you'd end up with 11:31.
The Fire is interesting and is likely to sell pretty well, but it -- and all Android tablets put together, even if you include those like the Nook that can't run most apps without hacking -- won't touch iPad sales this year.
Maybe next, we'll see.