I just gave you a resources with all of those information, but okay. I'll break it down. There are approximately 15 000 people in the UAE living in slavery or 1.67 person per 1000 as a proportion. The most common way to keep people into slavery is for their employer to seize the passports of migrant workers. Another popular technique is to illegaly charge foreign worker an immigration fee that must then be reimbursed. This is technically against the law in the UAE, but there isn't enough enforcement of such rule nor enough oversight from the government and major businesses to not deal with agency or proxies that do such practices. About 65% of those 15 000 people are forced workers. The rest are people forced into marriage.
How does the UAE compare to other countries. The level of vulnerability of the UAE to slavery is of 26.80 out of 100; so quite good. If we compare it to the US; the US has a level of vulnerability of 15.88 out of 100 though there is a LOT more slaves in raw numbers in the US then in the UAE with approximately 400 000 slaves in the US or 1.26 person per 1000 (so a lower proportion). If you want to compare it to another Middle Eastern country, like Israel for example, the UAE compares much more favorably. Israel has a much higher level of vulnerability at 36.42 and a larger proportion of slaves to its general population at around 3.86 per 1000. If you want to compare it to a western European country, like France for example, the UAE is much more vulnerable than the 5th Republic, which scores at around 15.26 out of 100, though there are more slaves in France per capita at 2.01 per 1000. This is due to the fact that the French government is very good at dismantling slave-traders organization and rescuing slaves, but the migrant crisis generated by the war in Libya, Mali and Syria has increased the number of very vulnerable people trying to flee to France using dubious sources. If we compare it to Australia, the UAE compares very poorly since Australia has a ridiculously small vulnerability at 4.27/100 and almost no slaves on its territory 0.65 per 1000. If we compare the UAE to a East European country like Russia, it emerges much better. Russia's vulnerability is almost twice higher and has five times the number of slaves per capita though it's also twice poorer unlike the precedent examples which were about as wealthy. Compared to China, the UAE emerges much better since both Russia and China have similar numbers with China coming out a bit better. The same goes for South Africa which has a smidge better than Russia, but worst than China despite being poorer than both those countries. It's per capita number of slaves is lower than of both those countries. South Africa is the case of a country with too little resources to tackle the problem, but honest intentions. The single worst country in the world is, without much surprise, Eritrea also colloquially known as "Africa's North Korea". Its the 10th poorest country in the world and ruled by one of the most oppressive regime there is.