BERLIN, Oct. 9 (Xinhua) -- German companies increasingly struggle to fill job vacancies due to historically low unemployment, according to a study published Tuesday by the Institute for Employment Research (IAB), the research institute of Germany's Federal Employment Agency.

According to the study, the so-called unemployed-to-vacancies ratio has fell to its lowest level since 1992, with two jobless Germans per occupational opening in 2017. The researchers further highlighted that the share of new positions in which companies in Germany encountered difficulty in hiring staff has increased from around 12 percent in 2003 to 43 percent in 2017 as a consequence of the country's booming labor market and strong economic momentum.

The findings were based on an annual and representative survey conducted by IAB. Every year since 2015, German companies polled by the Nuremberg-based researchers have now indicated that finding suitable staff is their single-greatest operational challenge.

"Since the mid-2000s we can observe an almost continuously rising demand for personnel which coincided with an only briefly-interrupted economic growth and falling unemployment," the study read. The researchers emphasized that these trends were conspiring to produce "growing labor market pressures" experienced by companies.

Whereas only six percent of employers said they had to offer higher wages to attract workers to positions in 2004, 16 percent reported having to do so in 2017. Aside from forcing employers to spend more on hires, low unemployment in Germany also meant that vacancies remained unfilled for longer than anticipated.

The IAB estimated that companies hired 3.65 million new staff into socially-insured (and hence generally more stable) forms of work in the course of 2017. Recently published data has revealed 1.2 million current job openings in Germany, the highest level in 25 years, when the survey was first conducted.

In 2017, the researchers analyzed responses from around 14,600 firms participating in the study.