Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year | Domestic passengers | International passengers | Total passengers | Change |
| --- | --- | --- | --- | --- |
| 2006 | 764,831 | 83,115 | 847,946 | +4.6% |
| 2007 | 764,674 | 75,276 | 839,950 | −0.9% |
| 2008 | 709,779 | 92,176 | 801,955 | −4.5% |
| 2009 | 605,534 | 82,424 | 687,958 | −14.3% |
| 2010 | 595,457 | 105,119 | 700,576 | +1.7% |
| 2011 | 850,305 | 123,607 | 973,912 | +39.1% |
| 2012 | 899 854 | 178,679 | 1,078,533 | +10.7% |
| 2013 | 745,178 | 131,902 | 877,080 | -18.7% |
Question:
how many years showed a positive increase?
Answer:
4