I don't know specifics about the SEN-KIV route, but I've seen in previous summers on similiar routes a big rush to return to the town/village where the rest of the family live (eg see elderly parents) over the summer and return to the place of work at the end of August / early September.
Many born in the UK will go to Ibiza over the summer for a week or two. Many Moldovans living in the UK will presumably rush to Moldova over the summer for 2 weeks. You can see something similiar in the Italy-Albania market