public List <SelectListItem> GetActivities(string operationNumber, int year)
        {
            var list           = new List <SelectListItem>();
            var listRepository = _missionService.GetActivitiesByOperationAndYear(operationNumber, year);

            if (listRepository.Activity != null && listRepository.Activity.Count > 0)
            {
                list = listRepository.Activity.Select(o => new SelectListItem
                {
                    Selected = false,
                    Value    = o.ActivityId.ToString(),
                    Text     = o.Description
                }).ToList();
            }

            return(list);
        }