Please check out the program carefully as the cheapest economy fare available might not even earn you anything：

V, Z, T, N, R Class earns 25%
U, A, L, E, Q Class earns 50%
F, I, O, S, Z, X, G CLass earns 0%.

5 X return trip a year with V class will not even make you the lowest tier with CZ. You need to understand what type of fare class you would normally book into. Most people gain their status with CZ through sectors flown domestically in China or Business/First Class flights.