Total capital expenditures for property, plant and equipment and intangible assets (excluding intangibles acquired through business combinations) amounted to $772 million, $752 million and $632 million in 2018, 2017 and 2016, respectively. In 2018, 2017 and 2016, capital expenditures were 16 percent, 10 percent and 27 percent lower, respectively, than depreciation and amortization. Excluding acquisition-related amortization, capital expenditures were 20 percent, 24 percent and 1 percent higher, respectively, than depreciation and amortization.
Capital expenditures in 2018 remained at a significant level in mature markets, reflecting the geographic distribution of our existing production facilities. Capital expenditures in Europe and North America in 2018 were driven primarily by upgrades and maintenance of existing production facilities, mainly in the U.S., Finland, Italy, Sweden and Austria, including a state-of-the-art innovation and training campus in Austria, which will become one of our largest research and development centers. Capital expenditures in emerging markets were highest in China, Poland and India. Capital expenditures in emerging markets were made primarily to increase production capacity by investing in new or expanded facilities. We are planning to build an advanced, automated and flexible robotics factory in China, which is designed to combine our connected digital technologies, state-of-the-art collaborative robotics and innovative artificial intelligence research. The share of emerging markets capital expenditures as a percentage of total capital expenditures in 2018, 2017 and 2016 was 31 percent, 28 percent and 36 percent, respectively.
At December 31, 2018, construction in progress for property, plant and equipment was $464 million, mainly in the U.S., China, Sweden, Finland and Germany. At December 31, 2017, construction in progress for property, plant and equipment was $511 million, mainly in China, the U.S., Switzerland, Sweden and Germany, while at December 31, 2016, construction in progress for property, plant and equipment was $342 million, mainly in China, the U.S., Germany, Sweden and Switzerland.
Our capital expenditures relate primarily to property, plant and equipment. For 2019, we estimate the expenditures for property, plant and equipment will be higher than our annual depreciation and amortization charge, excluding acquisition-related amortization.