ListView with a huge amount of items crashes during a random scrolling

import QtQuick 1.0

Item {
//    width: 300
//    height: 600
    ListModel {
        id: playlist
    }

    ListView {
        id: listview

        anchors.fill: parent
        model: playlist
        delegate: playlistDelegate
        highlightMoveDuration: 500

     }

    Rectangle {
        id: button
        width: 100; height: 50
        color: "green"
        anchors.bottom: parent.bottom
        MouseArea {
            anchors.fill: parent
            onClicked: listview.currentIndex = Math.random() * (listview.count - 1)
        }

        Text {
            anchors.centerIn: parent
            text: "Go random"
        }
    }

    Component {
        id: playlistDelegate

        Item {
            height: 75
            width: listview.width
            Row {
                Text {
                    text: index + 1 + "."
                    color: "green"
                }
                Text {
                    text: "  " + num
                    color: "green"
                }
            }
        }
    }

    Component.onCompleted: {
        for (var i = 0; i < 50000; i++)
            playlist.append({"num":  Math.random(), "num1": Math.random(), "num2": Math.random(), "num3": Math.random(), "num4": Math.random(), "num5": Math.random(), "num6": Math.random(), "num7": Math.random()})
    }
}