Describing trends

12345678910111213141516
Across
  1. 2. To become twice as much
  2. 4. A downward movement; opposite of "rise"
  3. 5. To become bigger over time
  4. 10. By a small amount; not significantly
  5. 12. To stay the same without changing
  6. 13. To improve or increase something, especially quickly
  7. 15. In a slow and gradual way
Down
  1. 1. To make something smaller or less in siez, amount or number
  2. 3. To fall very fast and very suddenly
  3. 6. To gradually become less or worse
  4. 7. By a large amount, significantly
  5. 8. Staying the same without large changes
  6. 9. To move upward
  7. 11. To become larger in size, amount, or number
  8. 14. Another word for failling steeply, almost vertically
  9. 15. Up to move upwards (2 words)
  10. 16. A sudden and sharp fall