Victory Area is getting over y axis in react native

I'm using victory stack area chart but it's value is getting over y axis. In pic green has y = 3 but it's getting over 4. How can I fix this?

my code for that

  <VictoryChart
          theme={VictoryTheme.material}
          height={300}
            />
          }
          width={370}>
          <VictoryStack height={200}>
              <VictoryArea
                name={strings.WASTED}
                style={{
                  data: stackedAreaStyle.victoryAreaWaste,
                }}
                data={wastedData}
                y={(datum: any) => datum.y}
                // x={(datum: any) => datum.day}
              /> 
              <VictoryArea
                name={strings.USED}
                style={{
                  data: stackedAreaStyle.victoryAreaUsed,
                }}
                data={usedData}
                y={(datum: any) => datum.y}
                // x={(datum: any) => datum.day}
              />
        
          </VictoryStack>
          <VictoryAxis
            fixLabelOverlap
            style={stackedAreaStyle.xAxis}
            tickCount={3}
          />
            <VictoryAxis
              fixLabelOverlap
              dependentAxis
              orientation="left"
              style={areaChartStyles.yAxis}
              tickCount={2}
              crossAxis={false}
              tickFormat={y => y}
            />
        </VictoryChart>

Sorry If I didn't explained my question properly