用MATLAB做BP神经网络预测模型训练次数为0

请问我用MATLAB做BP神经网络预测模型训练次数显示为0，这是为什么，谢谢？
代码如下：

clc  

clear all

num=xlsread('test.xlsx', ' A2: A205');

input_train = num(1:180,:)';

output_train= num(181:192,:)';

input_test=num(13:192,:)';

[inputn,inputps]=mapminmax(input_train);

[outputn,outputps]=mapminmax(output_train);

net=newff(inputn',outputn',9 )

net.trainParam.epochs=100;

net.trainParam.lr=0.1;

net.trainParam.goal=0.00004;

net=train(net,inputn',outputn');

inputn_test =mapminmax('apply',input_test,inputps);

an=sim(net, inputn_test');

BPoutput=mapminmax('reverse',an,outputps);