“…Thus, the four-clusters solution confirms the stability of clusters of the strongest and weakest countries. 3,4,5,6,7,8,9,10,11,12,14,15,16,17,18,19,20,21,22,24,25,26,27,28 Ireland 7 0.4729 1,2, 3,4,5,6,7,8,9,10,11,12,14,15,16,17,18,19,20,21,22,24,25,26,27,28 Bulgaria 2 0.4448 1,2, 3,4,5,…”