Soda ash (sodium carbonate) is made in two ways: from natural trona ore (natural soda ash), and from common salt by the Solvay process (synthetic soda ash). Tata Chemicals is one of the world's largest soda ash producers.
Two charts give the data. The first chart plots WORLD production of natural and synthetic soda ash for the years 2001 to 2006: the synthetic soda ash bars climb every year over this period, while the natural soda ash bars stay roughly flat. The second chart plots Tata Chemicals' own natural and synthetic output:
| Year | Natural Soda Ash (MT) | Synthetic Soda Ash (MT) |
|---|
| 2005 | 0 | 0.7 |
| 2007 | 0.4 | 2.2 |
| 2008 | 3.2 | 2.2 |
Which of the following statements are true?
1. Proportion of natural soda ash to synthetic soda ash has decreased from 2001 to 2006 globally.
2. Proportion of natural soda ash to synthetic soda ash has increased from 2001 to 2006 globally.
3. Proportion of synthetic soda ash to total soda ash has decreased for Tata Chemicals from 2005 to 2007.
4. Proportion of synthetic soda ash to total ash has increased for Tata Chemicals.