In this task, you are given a sentence in the English language and your task is to convert it into the Hindi language. In translation, keep numbers as it is.
Q: It is estimated that the annual average loss of production during the decade 1970-79 was 3.5 million tonnes .
A:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
अनुमान के अनुसार सन् 1970-79 के दशक में सीमेंट उत्पादन की वार्षिक हानि औसतन 35 लाख टन थी ।