The state of California (where Wayne's Word is based) includes about 5,000 native and naturalized species, and 41 percent of these species belong to the following six plant families: sunflower family (Asteraceae), grass family (Poaceae), legume family (Fabaceae), snapdragon family (Scrophulariaceae), mustard family (Brassicaceae), and sedge family (Cyperaceae).
Transferring your existing single phone number (wireless or landline) to T-Mobile number usually takes anywhere from 10 minutes to 24 hours. Transferring multiple  lines may take up to 10 days, however most requests are completed within six calendar days.
I say 3 years because I believe that the average user likely keeps their phone for the 2 years that most carriers make you wait before you can get a discounted upgrade. Then most people these days either trade that phone in or sell it online where it sees an extension to it's life, probably between 1 to 2 years.