The Most Bought Books Of The Past Decade

What do you think the most-bought books were of the past ten years? According to The NPD Group, a market research company which collects data on book sales:
1. “Fifty Shades of Grey”
2. “Fifty Shades Darker”
3. “Fifty Shades Freed”
4. “The Hunger Games”
5. “The Help”
6. “The Girl on The Train”
7. “Gone Girl”
8. “The Fault in Our Stars”
9. “The Girl with The Dragon Tattoo”
10. “Divergent”