thanks to everyone who gave a answer 😀 much appreciated
i got it working like this in the end
 int employmentInMonthsAmount = this.MaxEmploymentHistoryInMonths;
                var intcounter = 0;
                int years = 0;
                for (var i = 0; i < employmentInMonthsAmount; i++)
                {
                    if (intcounter >= 12)
                    {
                        years++;
                        intcounter = 0;
                    }
                    intcounter++;
                }
                var monthsleft = intcounter;
solved Looping – amount of years from months