The amount of profit and its dynamics were significantly impacted by the foreign exchange effect and the change in fair value of non-commodity financial instruments (including at the joint ventures level), as well as the effect of disposal of interests in joint ventures. Net of these effects, our adjusted profit attributable to NOVATEK shareholders in 2015 and 2014 totaled RR 135.0 billion and RR 104.8 billion respectively, representing a year-on-year increase of 28.9%.
For the twelve months ended 31 December 2015, total revenues increased by 32.9% year-on-year to RR 475.3 billion largely due to a record increase in liquids sales volumes, growth in natural gas sales prices, as well as an increase in liquids net sales prices in rouble terms driven by higher US dollar to Russian rouble exchange rate and lower export duty rates.
In 2015, we recorded a year-on-year increase of 34.4% in the Company’s Normalized EBITDA, including our respective share in the EBITDA of joint ventures, which totaled RR 214.5 billion. The growth in our Normalized EBITDA was positively impacted by a higher share of liquid hydrocarbons in our overall sales volumes mix, as well as an increase in sales volumes of high value-added petroleum products from the Ust-Luga Complex.
Our free cash flow increased by 67.2% to RR 82.3 billion as a result of operating cash flow growth by 19.4% and a decrease in cash used for capital expenditures by 18.5% as compared to 2014.
In 2015, our natural gas sales volumes totaled 62.5 bcm as compared to 67.2 bcm in 2014. Lower natural gas sales volumes were mainly a result of warmer weather conditions in 2015 compared to 2014, as well as one of our major customers not taking temporarily its full contracted volumes due to technical reasons. As at 31 December 2015, the total amount of natural gas recorded as inventory aggregated 1.3 bcm.
Our liquid hydrocarbon sales volumes amounted to a record high of 12.9 million tons, representing an 81.8% increase as compared to 2014. The significant increase was due to production growth at the Arcticgas fields, the launch of the Termokarstovoye field and an increase of crude oil production by subsidiaries. As at 31 December 2015, 910 thousand tons of liquid hydrocarbons were in transit or storage and recognized as inventory.