50% (50 out of 100 people) in Country X experience a heart attack over a 5 year period. 30 out of the 50 people experience a repeated heart attack in Country X. In State A of Country X, 20% (10 out of 50 people) experience a heart attack over the same 5 year period. 10 out of the 10 people experience a repeated heart attack in State A. All data is from the same database/source and period of data collection (5 years). I want to know if the proportions of repeated heart attacks between Country X and State A is significantly different over this 5 year period. Can I use the test of two proportions z-test when the sample of data is from the same database and over this period of time?