Array Data to Chart

I have a problem. I have a list of data that I output grouped. Now I want to output the values e.g. erzeugenGes to a barchart. Chart modules itself works. Fail only at the grouped data for evaluation. Enclosed my code and list

1,2,3,4,5,6,7,8,9,10,11,12 are the Month for the ChartLabels

1: [{…}]
2: [{…}]
3: [{…}]
4: [{…}]
5: [{…}]
6: [{…}]
7: [{…}]
8: [{…}]
9: Array(1)
0: {jahr: 2020, monat: 9, erzeugungGes: 901.04, verbrauchGes: 952.22, eigenverbrauch: 515.24, …}
length: 1
__proto__: Array(0)
10: Array(2)
0:
bezogen: 252.18
eigenverbrauch: 201.62
eingespeist: 140.94
erzeugungGes: 342.53
jahr: 2019
monat: 10
verbrauchGes: 453.75
__proto__: Object
1:
bezogen: 232.07
eigenverbrauch: 174.13
eingespeist: 102.37
erzeugungGes: 276.48
jahr: 2020
monat: 10
verbrauchGes: 406.19
__proto__: Object
length: 2
__proto__: Array(0)
11: Array(1)
0: {jahr: 2019, monat: 11, erzeugungGes: 291.87, verbrauchGes: 761.16, eigenverbrauch: 238.38, …}
length: 1
__proto__: Array(0)
12: [{…}]

/// and Data

getData() {
    this.ds.getAuswertungJahr().subscribe(res => {
    this.daten = res;
    this.data = this.daten.reduce((r, a) => { console.log("a", a); console.log('r', r); r[a.monat] = [...r[a.monat] || [], a]; return r; }, {}); console.log("group", this.data);

    this.barChartData[0].data = [];

    for (let i = 0; i < this.data.lenght; i++) {
      this.barChartData[0].data.push(this.data[i]);
   }
})

}

Thanks