National Oilwell Varco Inc. (NYSE:NOV)

The financial data reveals notable trends and fluctuations over the five-year period from 2011 to 2015. The revenue composition shows a consistent majority contribution from sales, ranging from approximately 79% to 83% of total revenue, with a slight decline over the years. Services as a percentage of revenue increased gradually, particularly notable in the last two years, reaching over 20% in 2015.

Cost elements exhibited varying trends. The cost of sales, as a percentage of revenue, increased substantially from 54.83% in 2011 to 63.44% in 2015, implying rising expenses associated with core sales activities. Similarly, the cost of services showed a mild increase towards the end of the period. Overall, the cost of revenue rose from 69.32% to 79.24%, indicating growing pressure on cost management relative to revenue.

Reflecting these cost pressures, gross profit margins declined markedly, from 30.68% in 2011 to only 20.76% in 2015. This trend points to reduced profitability from core operations over time.

Selling, general and administrative expenses as a percentage of revenue remained relatively stable around 9-12%, although a sharp increase is noticeable in 2015, moving from under 10% to nearly 12%. A substantial non-recurring charge manifested in 2014 and sharply intensified in 2015 with goodwill and intangible asset impairments recorded at -0.49% and -11.45% of revenue respectively, likely contributing substantially to the deteriorating profitability in the latter year.

Operating profit margins followed a declining trajectory from a strong 20.04% in 2011 to a negative figure of -2.64% in 2015, reflecting the impact of both cost increases and impairments. Financial costs remained relatively low but increased slightly towards the end of the period, while interest income remained negligible throughout.

Other income and equity income from unconsolidated affiliates showed a modest decrease, with other income becoming a larger net expense by 2015. Consequently, income from continuing operations before income taxes declined from nearly 20% of revenue in 2011 to a negative -3.99% in 2015.

Income tax provisions decreased sharply over the period, falling from 6.39% to 1.21% of revenue, which may reflect changes in taxable income or tax strategies. Despite the lower tax provision, the net income from continuing operations showed a marked decline, turning negative in 2015 at -5.20%, aligned with the overall loss reported in net income attributable to the company, also negative at -5.21% of revenue.

Discontinued operations contributed marginally in 2014 but had no impact in other years. Noncontrolling interests remained negligible throughout the period.

Overall, the data highlights a trend of increasing cost pressures and deteriorating profitability, culminating in a loss in 2015 driven by higher operating expenses, significant impairment charges, and declining gross margins. The company's ability to sustain profitability appears challenged during the period under review.