3 leaves is not normal. 5-6 leaves is normal. Really healthy ones carry 8 leaves.
Yours is not holding enough leaves. Yes it is blooming every year, but how many flowers? I can't tell you how many would be appropriate without knowing what it's linesge is.
You need to fine tune your culture!!!
Repot every two years at least.
Fertilize 1/2 strength no more then 4x per year.
Make sure the leaf color is good and the light is proper.
Watch your watering, never let it get too dry.
Make sure it is between 60-80 degrees.
I say to fine tune your culture because when a Phalaenopsis is stressed when not in bloom, the first thing that it might do is drop a leaf. Or stressed in bud or bloom, there are fewer flowers, slightly smaller flowers, or buds drop off.
Also very important, after four years it should have 5-6 leaves easy. You obviously can grow it but a little extra care is needed!!
Good luck!!
