Imported animation has one more frame than the original fbx

In UE4.12, imported animation has one more frame than the expected frame number.
AS_AN_StepAnim_Test.fbx is 60 frame long animation(starts at frame 0, ends at frame 60). When imported to UE4.12, it's imported as a 61 frame long animation, and resulting animation is not exactly the same.

Two licensees are reporting this issue

1. Open animframe project in UE4.12
2. Import StepAnim_Test.fbx(with default sample rate: off)
3. StepAnim_Test's Num Frames is 61, not 60
4. In Persona, user can go up to Frame 61, even though the original animation ends at frame 60