19250-19050 = 200 200 is the price difference per ton of 200 yuan, per 10 ton, so it is 200 *10 = 2,000 yuan.

The 50 you mentioned above fluctuates by one point, and for each fluctuation, the price difference is 5 yuan. 200/5=40 is equivalent to Apollo moving 40 times instead of fluctuating 200 times.