Before revision:  We analyze a {\it base} set of 42 countries, which developed the epidemic earlier, {\it   and an {\it extended} set of 88 countries, which developed the epidemic more recently.
After revision:  We analyze a {\it base} set of 42 countries, which developed the epidemic earlier, {\it set of 88 countries and an {\it extended} set of 88 countries, which developed the epidemic more recently.