| Year | Electricity Distribution Tariff Index | Electricity Transmission Tariff Index |
|---|---|---|
| 2012 | 100 | 100 |
| 2013 | 104 | 103 |
| 2014 | 109 | 107 |
| 2015 | 112 | 111 |
| 2016 | 110 | 109 |
| 2017 | 114 | 112 |
| 2018 | 118 | 115 |
| 2019 | 122 | 120 |
| 2020 | 125 | 123 |
| 2021 | 121 | 119 |
| 2022 | 128 | 126 |
| 2023 | 135 | 131 |
With reference to Figure 1, explain one likely reason for the overall trend in the real price of electricity distribution and transmission services.