issues concerning the drought we have in Brazil and Sabesp has been an example for the rest of the world, for the sanitation companies in the world because it prepared itself. We adapted ourselves to climate change, so it is with great satisfaction that we saw that the final report of the chairman of COP26 gave more importance to the adaptation issue. And, not only this, the next COP that will happen in Egypt next year, the focus will be on everyone adapting themselves and how this will impact and, um, and bring an improvement to the less developed countries in the Southern Hemisphere. Also, within this context of ESG, the company is alert. The company is getting stronger and stronger in this direction, ESG. Well, I believe you are more interested right now in hearing our CFO and the positive results in finance. So, Dr. Osvaldo, you have the floor. Good morning, Chairman Braga. Good morning to all. I thank you all for participating in this, uh, video conference to discuss the earnings of Q3 2021. Beginning on slight-… ' 21. Beginning on slide three, we observe the total volume build with a growth of 3.7% in relation to Q3 ' 20, this considering the volumes of Maua, which is in this quarter is working in retail. And Q3… in Q3 2020, uh, they were working in, uh, not in retail. Well, this consider the volumes that are exempt from collection and also social and residential categories in shanty towns. Going from 957.3 million to 992.7 million cubic meters built, this growth is greater in the e- in sewer services, 4.1% in relation to the volume build in the segment of water that rose 3.4%. The most significant increase happened in the non-residential categories, with… where tariffs are higher, 15.7% in public, 7% in commercial, and 6.6% in industrial clients. In the residential segment which represents the greatest volume in relation to the total, the growth was 3.2%. With a recovery of consumption in non-residential categories, we noticed a recovery in the average tariff with favorable impact on revenue. Next slide, please. Now, we'd like to see the slide with financial numbers. The revenue from sanitation services had, uh, an increase of 17.7% end of the period, going from 3. 6 billion in Q3 ' 20 to 4.3 billion reais in Q3 ' 21, especially as a result of tariff increases applied on clients' bills in August, 2020, 3.4% and since May this year, an increase of 7%. The effects are… can be seen in the revenue in this quarter when compared to the same quarter last year. Also, we add the increase of 3.7% in the total volume build, which explains the relevant increase of the total revenue of sanitation services, and the operation of water distribution in retail in the City of Maua, which in- which is now 24.7 million more in comparison with the same period last year. Net revenue went from 4.4 billion reais to 5. 2 billion reais due to the growth in the volume builds, and the inclusion of the price increases mentioned, as well as with the revenue from construction that contributed for the growth of 132.7 million in the period. The costs, administrative expenses and commercial expenses, including the inaudible construction, had an increase of 13.8%, going from 3.5 billion in Q3 2020 to 3.9 billion in Q3 2021. When we exclude the construction costs, the increase was 14.3% or 347.5 million reais. Adjusted EBITDA was 275.7 million above the EBITDA of Q3 ' 20, resulting in 1.8 billion in Q3 ' 21, a positive variance of 18.2%. Now, concerning the EBITDA margin which does not consider the revenue and construc- f- and construction cost, was a little higher, going from 44% to 44.4%. The net profit, net income closed at 486.6 million, 11.1 above the profits in Q3 ' 20, which was 421.6 million reais. I'd like to stress that this increase was based on the revenue that grew in a more vigorous way, with the inclusion of recent prices readjustments, a greater volume, recovery of non-residential segment, thus improving the average tariff, and despite the pressure on cost and expenses due to higher inflation, and also with higher interest rates and exchange variations. Now, we go on to the slide for costs and expenses. The cost and expenses when we disconsider the cost of construction had an increase of 14.3% or 347.5 million. It's important to remind you that the analysis in comparison of this quarter with that of 2020, in some cases may lead to distortions because many activities were paralyzed or delayed last year as a result of the measures, uh, for social isolation. The expenses with personnel had a small increase, 1.8%. The explanation is in the salary increase of 7.75% in May this year, and medical expenses that were exceptionally low in the previous year. This variation above the… below the inflation of the period is due to the reduction of around 1,000 employees. The effects of the impact of the pandemic in Q3 ' 20 can also be observed with different degrees of magnitude in the expenses with materials and expenses with services. In general expenses, a significant part of the growth observed of 103 million or 45.9% is explained by the expenses with court, court issues, 53.3 million, and the increase in accruals or provisions for payments to the Environmental and Infrastructure Sanitation Municipal Fund, resulting in the growth of the revenue and the number of cities included worth 32.9 million. Expenses with electricity were also important. The average increase in the tari- tariffs ACR was 30.6%, and the impact was not greater because we migrated part of the consumption to ACL, the free environment, where the price increases were not that high. In general, the expenses with electricity had an increase of 20.6%, going from 311 million to 375 million reais in the period. Different from the revenue that already reflects the recovery in volume and average tariffs in relation to the same period last year, the estimated losses with credits and bad debts increased by 43.5 million, a growth of 57.9%. As mentioned by our chairman, due to the beginning of the operation of the new cor- commercial system, we will have a more modern tool to approach and solve these balances that were not collected, were not received. Next slide, please. Financial performance. The graph for financial performance begins with the profit in Q3 2020 of 421.6 million, and shows the movement of the results in the period. Net operational revenue grew 715.4 million due to tariff increases, totally included, growth in volume, and improvements in the average tariff as already mentioned. Cost and expenses plus construction cost had an increase of 477.3 million. Other revenues and operational expenses, including equity, had a positive variation of 2.8 million reais. This financial result presented a negative variation of 190 million due s- specially to the devaluation of 8.7 and 8.3% of the Brazilian currency in comparison with the US dollar and the yen respectively, a devaluation that is greater than the one observed in Q3 ' 20, which was 3 and