You'll have a hard time finding resources for a recent walmart schwinn. Honestly nobody cares when it was made. You might have better luck finding info on the components on the bike and dating it that way.
86 Samurai 1.3 leftovers
14 RAV4 2.5 0W-20 PPP
16 Silverado 1500 4.3 Ecotec3, DI, AFM 5W-30 PPP
Why know when you can guess?!