我想使用for循环来查找python中某个范围内的数字频率。例如：对于下面的列表，我想找到45-50,55-60之间的数字频率等等......
my_lst = [['52.2', '57.6', '54.3', '56.2', '48.4', '57.3', '50.8', '52.8', '60.9', '56.9'],
['54.2', '57.8', '55.4', '56.3', '51.7', '61.2', '53.7', '54.6', '61.6', '60.4'],
['56.2', '58.7', '61.1', '58.9', '54.8', '63.7', '58.3', '55.1', '65.8', '60.7'],
['60.2', '61.3', '61.9', '61.6', '57.5', '66.7', '61.2', '57', '66.9', '62.4']]