Thomastik Dominant Synthetic Core Aluminum Wound Violin String 4/4 Medium A 2nd

I have had Thomastik's Violin-Saite Dominant strings on my violin for over 15 years now. I love their rich, mellow sound, definitely my favorite strings in this price range. Last week, my A string snapped while tuning, which is hardly surprising given that they're several years old. The description says they should be change at "appropriate intervals." I am not sure exactly how long is considered appropriate; however, I didn't notice any appreciable change in sound quality or intonation in the time they have been on my violin. I do clean my strings thoroughly after playing and have dry hands in general, which seems to help with longevity. The strings hold tuning well and are responsive. Overall, they are a very good value with a fantastic sound.