stroke rate meaning in English

冲数
划手频率

The stroke rate dropped from 50 per 100 , 000 to about 46 . 5 , and the number of stroke deaths dropped from about 150 , 000 to 143 , 500
中风率从十万分之50降到了46 . 5 ，死于中风的人数从150000降到了143500 。
It is importance to accurately conform the wave impedance of tower , when the wave impedance of tower change sign 10 percent independently , the back stroking rate of transmission line will change sign 20 percent accordingly
正确确定杆塔的波阻抗是很重要的，当杆塔的波阻抗独立地变化10 %时，输电线路的反击跳闸率将相应地变化约20 % 。