| CPI | kostprijs elektriciteit | |
| jan/06 | 84,54 | 71,59 |
| jan/07 | 85,95 | 76,54 |
| jan/08 | 88,92 | 77,12 |
| jan/09 | 90,98 | 92,42 |
| jan/10 | 91,54 | 84,37 |
| jan/11 | 94,49 | 89,67 |
| jan/12 | 97,94 | 100,45 |
| jan/13 | 99,37 | 102,22 |
| jan/14 | 100,50 | 99,06 |
| jan/15 | 99,85 | 91,87 |
| jan/16 | 101,59 | 115,91 |
| jan/17 | 104,28 | 138,38 |
| jan/18 | 106,60 | 136,43 |