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:
|  | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Hydro power | 1,150 | 1,161 | 1,171 | 1,247 | 1,281 | 1,293 | 1,316 | 1,326 | 1,357 | 1,379 | 1,382 | 1,401 | 1,584 |
| Thermal | 685 | 835 | 1,056 | 1,233 | 1,215 | 1,155 | 1,155 | 1,155 | 1,285 | 1,290 | 1,390 | 1,690 | 1,638 |
| Other renewables | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 15 | 45 | 50 | 90 |
| Total availability | 1,838 | 1,999 | 2,230 | 2,483 | 2,499 | 2,411 | 2,434 | 2,444 | 2,645 | 2,684 | 2,818 | 3,141 | 3,312 |
| Hydro power | 3,197 | 3,110 | 2,962 | 3,310 | 2,960 | 3,451 | 4,634 | 3,947 | 4,130 | 3,881 | 5,634 | 4,622 | 3,292 |
| Thermal | 3,485 | 3,407 | 3,201 | 4,298 | 5,080 | 5,314 | 4,751 | 5,864 | 5,763 | 5,975 | 4,995 | 6,785 | 8,339 |
| Other renewables | 3 | 3 | 4 | 3 | 3 | 5 | 4 | 4 | 8 | 27 | 86 | 121 | 169 |
| Total production | 6,685 | 6,520 | 6,167 | 7,611 | 8,043 | 8,770 | 9,389 | 9,815 | 9,901 | 9,883 | 10,715 | 11,528 | 11,800 |
Question:
tell me the number of years that hydro power had an annual generation over 4,000.
Answer:
4