On the average, the human heart pumps about 70mls of blood with each beat. Considering that at rest, per minute, the heart beats 70 times. Over a year would be pumped a volume equal to 2,575,440,000 litres.
According to FINA (Fédération Internationale de Natation), the dimensions of an Olympic swimming pool are 25 meters wide, 50 meters long and 2 meters deep - volume equal to 2,500,000,000 litres.
Thus, at the end of a year the volume pumped by the human heart is slightly larger than the capacity of an Olympic pool.