Again, DV2018 was not “extremely slow”, you are comparing apples and oranges. AF, AS, and NA regions actually went current in DV 2018, while the EU region maxed out hence couldn’t go current. EU region was an over subscribed year in 2018 Per the
DOS Annual Visa Report, a total of
48, 578 visas got issued (this by the way does not include the number of selectees who processed via AOS).
If you want to compare 2018 VB progression with that of other years where VB went current, here’s a random sampling for you
2013 - Current - Issued Visas: 51,080
2016 - Current - Issued Visas: 45,664
2017 - Current - Issued Visas: 49,067
2019 - Current - Issued Visas: 44, 882
2015 - Not Current - Issued Visas: 48, 097