The IMEI contains a serial number, as you can see here: https://www.imei.info/?imei=357197069764457
My serial number is about 8.000 higher. Taking into account that a phone has two IMEI’s, this is about 4.000 phones before mine. The total number of FP2’s until June 2016 is 41.000. A back-of-envelope calculation then tells you it is unlikely to be a year older 