Highcharts -how to change world regions style in area stacked charts - highcharts

Question

I am trying to this chart:
How can I style the world regions so that all of them appear? In the pre view they appear in a straight line but the final view they show in the columns of 3. Not all of them appear. TIA!
//Grafica 1
$(function () {
Highcharts.chart('grafica1', {
chart: {
type: 'area',
},
title: {
text: ' '
},
xAxis: {
categories: ['1350', '1400', '1450', '1500', '1550', '1699', '1750'],
tickmarkPlacement: 'on',
title: {
enabled: false
}
},
yAxis: {
title: {
text: 'Percent'
}
},
tooltip: {
pointFormat: '<span style="color:{series.color}">{series.name}</span>: <b>{point.percentage:.1f}%</b> ({point.y:,.0f} millions)<br/>',
split: true
},
plotOptions: {
area: {
stacking: 'percent',
lineColor: '#ffffff',
lineWidth: 1,
marker: {
lineWidth: 1,
lineColor: '#ffffff'
}
}
},
series: [{
name: 'Africa',
data: [502, 635, 809, 947, 1402, 3634, 5268]
}, {
name: 'L. America',
data: [106, 107, 111, 133, 221, 767, 1766]
}, {
name: 'Oceania',
data: [163, 203, 276, 408, 547, 729, 628]
}, {
name: 'S-E. Asia',
data: [18, 31, 54, 156, 339, 818, 1201]
}, {
name: 'Japan',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'China',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'Near East',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'Asian CIS',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'Russia',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'East Europe',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'Central Europe',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'W. Europe - Nordic',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'Nordic',
data: [2, 2, 2, 6, 13, 30, 46]
}, {
name: 'N. America',
data: [2, 2, 2, 6, 13, 30, 46]
}]
});
});