The Billboard Year ran from the week ending DEC 2 2000 to the week ending NOV 25 2001! Only two weeks were cut off from U2s total with the first week being NOV 18, 2000 and then NOV 25, 2000. This meant that ATYCLB had a combined 604,000 copies missing from its year end total. The difference in sales between many albums on that chart is small enough that if those two weeks had been included, U2 would have been in the top 15 for the year.
U2 had the #5 album in the USA back in 1992. Of course, every week, from the first big sales week until the cut off at the end of the following year made the chart.
Of course, if you release the album in JUNE, then your really in trouble because the chart year would cut your sells in two. So total sales are more significant, and of course WORLDWIDE sales is really the key. Its good to know that worldwide, there really are a lot of people with good taste in music.