... is this estimated being counted if I would pay this price 12 months in a row?
No. How it works is explained pretty clearly on these two pages:
https://www.ovoenergy.com/help/article/levy-reduction
https://www.gov.uk/government/news/your-energy-bill-from-april-whats-changing
The levies that are being reduced are charged to suppliers per kWh, so the reduction is passed on to you by reducing your price per kWh. This applies to all tariffs.
I don’t think I’ve seen a mention of a £170 reduction. The budget spoke of ‘an average household saving of £150.’ The figure of £117 you’ve seen is the reduction in the price cap for the April quarter for the typical household; it incorporates the levy reduction and several other changes to both network costs and wholesale prices.