Phones were always a big trouble and hard to get in the days of SFRY. When Tito died, the country had more cars than phone numbers. The switchboards weren't added, nor the old ones replaced, at anywhere near a satisfactory speed, and the PTT (post, telegraph, telephones) was a huge bureaucratic apparatus. One had to jump through some hoops and maybe bribe here and there to wait less for a line.
It started changing in the nineties - with a single cell phone provider (in some kind of a deal with Milošević). By mid-nineties cell phones were already ubiquitous; the demonstrations 1996 were mostly organized by keeping the parties' security informed via cell phones.
Nowadays, the country still has only 3 million landline numbers (although these are now far easier to get, the switchboards are mostly digital, there's optics laid down between cities), but about 9 million cell phone numbers. Roughly one per capita.
One thing that never existed here, and AFAIK still doesn't exist, is the number of the phones in booths. They aren't published at all. I don't even know whether those phones have bells. It always amazed us when a booth phone rings in a Hollywood movie.