As anyone who's watched Eurovision will know, the voting is at least half of the show. Each country is contacted and asked for their results. ("Hello Riga. Can we have the votes of of the Latvian jury, please?") The top rated song gets 12 points, second 10, third 8, and so on.
For 42 voting countries, you can imagine this takes a long time, especially when some countries like to take their moment of fame and prolong it with painful banter.
At the halfway point, Norway is the runaway leader, with Iceland and Turkey tied for second. The UK is in the top 5, but Sweden is way down the leaderboard.