How to plot metastasis-free survival - (Sep/25/2013 )

Dear experts,

I need to plot metastasis-free survival using Prism.

I have 100 mice for experiment (I don't want to say control group for this posting). Inject metastatic cancer cells into tail vein to the 100 mice. I need to check metastatic nodules in mouse lung at different time points.

10 mice each at 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 weeks = total 100 mice!

I will sac and check their lungs.

if I see 10, 9, 8, 7, 6, 5, 4, 3, 2 and 1 mice with no metastasis at each time point,how do I plot metastasis-free survival?

Thanks advance for your help!

google kaplan meier plot