How can I plot geothermal gradient values in Matlab?

I am trying to plot three geothermal gradient values to evaluate the thickness of gas hydrate stability zone. I think I may written the wrong code for this because the higher geothermal gradient is plotting as the deeper line and the lesser geothermal gradient is plotting as the shallower line. The reverse is supposed to be the case. Please, see the attached figures.

This is the code:

data1=dlmread('HPBdata.txt');

data10=dlmread('WDSTGGR.txt');

figure

hold on

plot(data1(:,1),data1(:,2),'-r','displayname','100%CH4');

set(gca,'ydir','reverse');

xlabel('Temperature (\circC)');

ylabel('Depth (m)');

plot(data1(:,1),data1(:,3),'--g','displayname','90%CH4, 10%C2H6');

plot(data1(:,1),data1(:,4),'-g','displayname','95%CH4, 5%C3H8');

plot(data1(:,1),data1(:,6),'-m','displayname','79.29%CH4, 9.33%C2H6, 2.80%C3H8, 1.12%iC4H10, 7.46%nC4H10');

plot(data1(:,1),data1(:,7),'-c','displayname','74.43%CH4, 5.82%C2H6, 3.72%C3H8, 1.72%iC4H10,1.15%nC4H10, 4.77%H2S, 6.68%CO2, 1.72%N2');

plot(data1(:,1),data1(:,8),'--r','displayname','90%CH4, 8%C2H6, 2%C3H8');

N=4;

Seafloordepth=(data10(N,1));

xMin=0;

xMax=30;

plot([xMin xMax],[Seafloordepth Seafloordepth],'-b','displayname','Seafloor Depth');

temp1=18;

temp2=data10(N,2);

plot([temp1 temp2],[0 Seafloordepth],':k','displayname','Hydrothermal gradient');

x=temp2;

y=Seafloordepth;

xList=temp2:1:xMax;

m=data10(N,3);

xl=x;

yl=y;

yList=m*(xList-xl)+yl;

plot(xList,yList,'-.k','displayname','Geothermal gradient @30 \circC/km');

m=data10(N,4);

xl=x;

yl=y;

yList=m*(xList-xl)+yl;

plot(xList,yList,'--k','displayname','Geothermal gradient @33 \circC/km');

m=data10(N,5);

xl=x;

yl=y;

yList=m*(xList-xl)+yl;

plot(xList,yList,'-k','displayname','Geothermal gradient @36 \circC/km');

grid on

grid minor