BinCounts

BinCounts[data] counts the number of elements of data whose values lie in successive integer bins.

BinCounts[data, binspec] counts the number of elements of data whose values lie in successive bins specified by binspec.

Examples

Count integers in default bins:

BinCounts[{1, 2, 2, 3, 3, 3}]
(* {1, 2, 3} *)

Specify bin width:

BinCounts[{0.1, 0.5, 1.2, 1.8, 2.5}, 1]
(* {2, 2, 1} *)

Please visit the official Wolfram Language Reference for more details.