Figure 1: UK electricity transmission and distribution real price indices, 2012–2023 (2012 = 100)
| Year | Electricity Transmission Tariff Index | Electricity Distribution Tariff Index |
|---|---|---|
| 2012 | 100 | 100 |
| 2013 | 104 | 103 |
| 2014 | 109 | 106 |
| 2015 | 112 | 111 |
| 2016 | 116 | 113 |
| 2017 | 115 | 112 |
| 2018 | 118 | 115 |
| 2019 | 122 | 119 |
| 2020 | 126 | 123 |
| 2021 | 125 | 121 |
| 2022 | 129 | 126 |
| 2023 | 134 | 131 |
With reference to Figure 1, explain one likely reason for the overall trend in the real price of electricity transmission and distribution services.