Why is Java faster with a function using an external variable containing X rather than using X directly?

So i've made the following benchmark to try and understand how Lambas impact performance.

@Fork(1)
@Measurement(iterations = 5)
@Warmup(iterations = 5)
public class LambdaBenchmark {

    @State(Scope.Thread)
    public static class MyInteger {
        public Integer value = 10;
    }

    @Benchmark
    public void TestValueInside(MyInteger integer) {
        Function<Integer, Integer> toTest = i -> i + 10;
        toTest.apply(1);
    }

    @Benchmark
    public void TestValueOutside(MyInteger integer) {
        Function<Integer, Integer> toTest = i -> i + integer.value;
        toTest.apply(1);
    }

    @Benchmark
    public void TestValueOutsideFinal(MyInteger integer) {
        int i2 = 10;
        Function<Integer, Integer> toTest = i -> i + i2;
        toTest.apply(1);
    }

    @Benchmark
    public void TestValueOutsideLocalCopy(MyInteger integer) {
        int i2 = integer.value;
        Function<Integer, Integer> toTest = i -> i + i2;
        toTest.apply(1);
    }
}

I'm kinda puzzled by the results:

Benchmark                                   Mode  Cnt           Score           Error  Units
LambdaBenchmark.TestValueInside            thrpt    5  1494683335,686 ▒ 157769032,327  ops/s
LambdaBenchmark.TestValueOutside           thrpt    5   755197977,631 ▒  39587849,696  ops/s
LambdaBenchmark.TestValueOutsideFinal      thrpt    5  3007751583,191 ▒ 178696557,885  ops/s
LambdaBenchmark.TestValueOutsideLocalCopy  thrpt    5   771307179,267 ▒  13613431,113  ops/s

Why is TestValueOutsideFinal so much faster than TestValueInside ? We're using an external variable that may be considered final but it's still a variable rather than a direct value ? Or is the value 10 constantly being recreated rather than always using the same addressed variable ?

EDIT:

After taking into account what @AlBlue said, it's indeed showing much closer results.

Here are the results once I return each value:

Benchmark                                   Mode  Cnt          Score          Error  Units
LambdaBenchmark.TestValueInside            thrpt    5  309129197,389 ▒ 32089680,994  ops/s
LambdaBenchmark.TestValueOutside           thrpt    5  283435336,319 ▒ 52230809,938  ops/s
LambdaBenchmark.TestValueOutsideFinal      thrpt    5  360590518,854 ▒  3072257,599  ops/s
LambdaBenchmark.TestValueOutsideLocalCopy  thrpt    5  279159794,477 ▒ 12871790,409  ops/s