original: rainfall comes only 2-3 times a year , never exceeding 20 mm .
simplifications: it rains 2-3 times a year and never more than 20 mm . rainfalls only two to three times a year and it never adds up to more than 20 mm . it only rains 2-3 times a year , never more than 20mm . rain comes only 2-3 times a year , never more than 20 mm . it only rains 2-3 times a year and never more than 20mm rainfall comes only 2-3 times a year , never exceeding 20 mm . it rains 2-3 times a year , never going past 20mm of rain . rainfall comes only 2-3 times a year , never exceeding 20 mm .