confused with dates and years?

ok so im a bit confused w the dates and years, like for example, i have 2 sisters older than me, one was born 1992, the other, 1993. i was born in 1995. the one born in '92, is she 3yrs older than me? or 2yrs? if shes 2yrs older, than that means the one born in '93 is a yr older than me? what about the ones in the '94? ALSO, my husband was born in 1988, does that mean were 6yrs apart or 7yrs?