\({\triangle }{ABC}\)所在平面上一点\(P\)满足\(\overrightarrow{{PA}}{+}\overrightarrow{{PB}}{+}\overrightarrow{{PC}}{=}\overrightarrow{{AB}}\)，则\({\triangle }{PAB}\)的面积与\({\triangle }{ABC}\)的面积比为\(({  })\)