The number of attempted illegal entries into the EU in 2021 reached nearly 200,000, or 57 percent up from 2020, and the highest annual level since 2017, the EU border agency Frontex said on Tuesday.

The single largest number of illegal border crossings in 2021 was registered on the so-called Central Mediterranean route, which refers to sea crossings between North Africa and Italy, with more than 65,000 illegal migrants, a jump of 83 percent compared to 2020.

It was followed by the Western Balkan route, which involves overland routes traveled by migrants from Turkey and Greece via Albania, Bosnia and Herzegovina, and Croatia towards western Europe. The route saw more than 60,000 illegal border crossings in 2021, or 125 percent up from 2020.

The Eastern Mediterranean route – which refers to illegal arrivals to Greece, Cyprus, and Bulgaria – and the Western Mediterranean route – which involves sea routes into Spain – saw increases of 0.5 percent and 6 percent respectively. A new route, which was hardly used before, on the EU’s borders with Belarus, registered nearly 8,000 illegal border crossing, which is a rise of 1,069 percent year-on-year.

In 2021, most of the people detected arriving into the EU illegally were nationals of Syria, followed by Tunisia, Morocco, Algeria, and Afghanistan. Unchanged from 2020, women accounted for less than 10 percent of all illegal migrants, a significant drop in their percentage compared to 2019, according to Frontex.

The share of minors remained largely the same, state agency Hina said, without clarifying.

On the Central Mediterranean route, most of the illegal migrants were Tunisians, followed by Egyptians, whose number increased seven-fold compared to 2020, and then migrants from Bangladesh, Algeria, and Morocco. On the Western Balkan route, the number of illegal border crossings had been rising until September last year, and then it fell slightly.